After weeks of paperwork, Meriwether Lewis at last felt the touch of the future when, in mid-March, 1803, he reached the U.S. arsenal at Harpers Ferry, Virginia (now West Virginia). There, on the rifle range, above the placid junction of the Shenandoah and Potomac rivers, he was handed one of the brand-new Model 1803, short-barreled, .54-caliber flintlocks that Jefferson's secretary of war, Henry Dearborn, had just adopted as the army's official rifle. He hefted it. Good balance. He tamped in powder, dropped in a ball. Quick, easy loading. Aim. Fire. Commendable accuracy in spite of the short barrel. He must have nodded satisfaction, for the livelihood of his party might depend in large part on the rifles the men carried.
He ordered fifteen guns for fifteen men, together with powder horns, pouches, bullet molds, wipers, and, of utmost importance, spare parts and the special tools needed for repairs. To this requisition he added two dozen large knives and three dozen pipe tomahawks, some for his own party, some as gifts for important Indians. The tomahawks could be used for a peaceful smoke as well as for splitting heads. Handles were hollow and a tobacco bowl was molded solidly onto the heel of the hatchet blade. 
What turned into a real monster was the iron boat frame he had designed earlier in Washington. The problem revolved around the detachable sections forming bow and stern. Each had to curve inward to a point while also creating the "sheer line," a curve that runs from the end of a boat's keel up to the tip of the bow and, in the case of the iron nightmare, to the tip of the stern as well. The keel of Lewis's boat was thirty-two feet long. The overall length was thirty-six feet. Therefore each sheer line had to rise two feet two inches, the depth of the boat, within a horizontal distance of two feet even. He used a cord suspended in a curve between two points to show the arsenal boatwrights the line to strive for.
The blacksmiths heated bars of wrought iron until they glowed cherry red and then hammered out long, thin slats that would be supported at intervals by iron stanchions. Bolt holes had to fit exactly so the sections could be assembled and disassembled. Eyelets were also bored along the gunwales and other parts of the frame. After the craft had been put together at a launching point, a lattice of sticks could be added to the frame as support for a cover of bark and/or buffalo hides; the whole could then be drawn tight by cords run through the eyelets. Whether or not the boat was also fitted for a mast, as wooden pirogues were, does not appear.
The construction demanded more time and care than Lewis had anticipated. He hovered anxiously around the arsenal's foundry while the workmen built and fit together one curved end section and one semicylindrical midsection, the latter four feet ten inches of beam and twenty-six inches wide at the bottom. From this partial work he calculated that the completed frame would weigh, without a sheathing, a mere ninety-nine pounds, an easy carriage. Feeling cocky, he named the boat Experiment, ordered it finished, and moved on.  But in the meantime he had not written a single line to the man who was most interested in hearing from him.
One wonders about the six weeks' delay. Jefferson, and hence Lewis, hoped the expedition would be several hundred miles up the Missouri before winter set in. With that as a goal, they had allotted one week for the work at Harpers Ferry. The president would be expecting regular reports, and Lewis knew it. He sent none, perhaps because he did not wish to create worries while success seemed elusive. He may have feared, too, that if Jefferson learned of the setbacks he would order the experiment abandoned. Or conceivably, the troubles may have put him into such a fit of depression that for a time he could not rouse himself to do much of anything.
Whatever the cause, the president was worried. On April 23, expecting Lewis would be in Philadelphia by then, he addressed a letter to him there, complaining of not having had word of him since March 7. "I have no doubt you have used every possible exertion to get off, and therefore we have only to lament what cannot be helped, as a delay of a month now may lose you a year in the end." 
By that time Lewis was in Lancaster, Pennsylvania, home of the surveyor Andrew Ellicott. His first move on arriving was to write Jefferson a long explanation of what he had been up to. Among other things, he stated, he had written many long, important memos to boat builders, recruiting officers, supply agents. (But none to the president.) He had, moreover, triumphed over the difficulties of the iron boat. Yes, he was late, but there was no need to worry. "I still think it practicable to reach the mouth of the Missouri by the 1st of August." 
His host, Andrew Ellicott, was one of the friends Jefferson had called on to prepare Lewis for what lay ahead. He was an able cartographer. When Virginia and Maryland had ceded the District of Columbia to the United States to be the new seat of government, Ellicott had surveyed and mapped the area. He had acted as assistant to the city's planner, Pierre Charles L'Enfant, and afterwards had taken several trips to the Mississippi, whose course from the mouth of the Missouri to the gulf he had surveyed more accurately than it had been done before. St. Louis had learned its definitive place on the globe from his calculations.
He did not believe in the kind of crash course Jefferson wanted him to give Lewis. The young man would need patience and practice, he told Jefferson—lots of practice, especially with the instruments used for determining latitude and longitude. This practice he proceeded to give him, working him hard for seventeen days, often after dark. Once again this was more time than Lewis had counted on when drawing up his schedule. And Philadelphia, where he would purchase the bulk of his supplies and receive more tutoring in different subjects, still lay ahead.
He reached the thriving city about May 9 and straightaway began spending the twenty-five hundred dollars Congress had appropriated for the trip. His indispensable helper was Israel Whelen, the government purchasing agent stationed in the city. Working together, they bought upwards of two hundred different items from twenty-eight vendors. More material came from the Schuylkill arsenal just outside the city. Altogether, it was a staggering accumulation, including a $250 chronometer needed for calculating longitude, rough clothing for his men, books on botany and navigation for himself, tools and gun flints, and articles for the Indians they would meet. Though the last-named items were ostensibly good-will offerings, the heterogeny (its total cost came to $669.50) would also serve as a traveling showcase of the wares the United States was prepared to deliver to the Western tribes in exchange for furs —2,800 fishhooks, 12 dozen pocket mirrors, 22 yards of scarlet cloth, 130 rolls of tobacco, 73 bunches of assorted beads (not enough of them blue, the Indians' favorite color), and on and on. Packing it properly for equitable distribution among an unknown number of potential customers would turn out to be a major problem.
The whites would take along a few specialties of their own. One was 193 pounds of soup concentrate, ordered from cook Francois Baillet at a cost of $289.50. Baillet boiled hunks of beef down to a thick liquid, clarified it with the whites of eggs, added chopped vegetables, and continued boiling until he had obtained a thick paste. He then sealed the stiff goo into lead canisters; after the contents were diluted and eaten, the containers could be melted down and molded into bullets.
Another of Lewis's inspirations was an air rifle specially made for him by Isaiah Lukens, manufacturer of machine tools, dies, medals, watches, and so on. Though the weapon, novel at the time (but not to boys with BB guns today), looked like a long-barreled Kentucky rifle, it was activated by air pumped under pressure into a reservoir in the gun's butt. Firing produced no smoke and only a pop—useful characteristics if one wished to be secretive or to awe the Indians with what seemed another example of "white man's powerful medicine." 
Even more curious than soup or airguns to modern readers are the medical supplies on which Lewis spent $94.49, for they reveal the abysmal state of medicine at the opening of the nineteenth century. The captain's adviser in this field was Jefferson's friend, Dr. Benjamin Rush. A native of Pennsylvania, Rush had graduated from Princeton at the age of fifteen. After a hard five-year apprenticeship under a Philadelphia doctor, he crossed the Atlantic to the University of Edinburgh, where he won his M.D. at the age of twenty-two. Returning home, he became the first professor of chemistry in the United States. His institution: the College of Philadelphia, soon to be absorbed by the University of Pennsylvania, which appointed him head of its medical department. He was one of the four doctors who signed the Declaration of Independence; he helped found the country's first antislavery league and was a leading member of the American Philosophical Society. He wrote prodigiously on all manner of subjects. A fluent and popular lecturer, he helped prepare an estimated three thousand doctors for the young United States. The harm they inflicted on the populace is incalculable. 
In those days no one had the foggiest notion of bacterial or viral infective agents. An ailing body was cured by draining away the morbidities that had invaded it. "Bad" blood was Rush's particular bête noir, as it had been for most physicians since the days of ancient Greece. Using a lancet (a small, sharp-edged, folding knife), he slit a sufferer's vein and let the blood flow into a bowl,where he studied its "diseased" state. Very ill patients were bled until they fainted. Bleeding was also resorted to in the case of dislocated and broken bones; it supposedly reduced muscular tension, thereby making manipulations easier. He practiced what he preached. During Philadelphia's yellow fever epidemic in 1793, he ranged heroically through the city's hospitals, a knife-wielding technician at his heels. When he caught the disease, he bled himself. On other occasions he bled one of his daughters when she was six weeks old and had twice bled a son by the time the infant was two months old. Both children survived—because of the remedies, Rush was sure. 
He treated syphilis by applying mercury compounds to lesions in the mouth. (Mercury, we now know, is a poison.) The resulting painful salivations, he believed, took away the ailment. Making a patient vomit was a cure for a wide variety of ills, and was often accompanied by bleeding. He ended constipation with his famed bilious pills, compounded out of calomel (which contains mercury) and jalap. The concoctions were popularly, and appropriately, known as Rush's Thunderbolts.
In following his recommendations, Lewis filled a specially made chest with 1,300 doses of physic, 1,100 doses of emetics designed to induce vomiting, 3,500 pills to cause sweating, and various drugs for increasing salivation and kidney output. Less harmful were 15 pounds of pulverized Peruvian bark, at a cost of $30 (it contained quinine for soothing malaria), and 30 gallons of strong spirit wine that could be diluted and spooned into patients as medicine. Instruments included lancets, a clyster syringe for enemas, and four pewter penis syringes for urethral irrigations for the relief of gonorrhea. 
To these cures Rush added written suggestions for maintaining health. Do not march when indisposed (though the men had a continent to cross) but rest in a horizontal position (Rush's emphasis). Use spirits for washing tired feet; take internally no more than three tablespoonfuls of liquor to refresh a chilled or weary body. At mealtime try water laced with molasses and a few drops of sulphuric acid. During difficult and laborious enterprises, eat sparingly. Wash your feet every morning with cold water. Beware of constipation.  In the event, the last admonition was the only one followed.
Rush also suggested, at Jefferson's request, some of the things Lewis should concentrate on while studying Indians. What diseases did they have? ("Is the bilious fever ever attended by a black vomit?") What remedies do they use? At what age do women begin and cease to menstruate? Take a sampling of pulse rates of both children and adults morning, noon, and night. What about their bathing habits? Do they ever commit suicide for love? Is murder common? Do they sacrifice animals during their worship? How do they dispose of their dead? 
Robert Patterson's advice about surveying—he was professor of mathematics at the University of Philadelphia—was far more practical than Rush's about health. Only a hint of it has survived, however, in a problem in astronomy he sent Jefferson, saying it was a sample of the training he would give Lewis. Elementary, he described it, "easy even to boys or common sailors of but moderate capacity," whereupon he filled several sheets of paper with figures and formulas. He also recommended certain statistical tables the explorer should take with him to speed his calculations.  Just learning to use those was something of a feat for a young man already overloaded with considerations.
At Jefferson's behest two more of the university's professors added their bits, Dr. Benjamin Smith Barton, a physician and naturalist, and Caspar Wistar, the professor of anatomy. Barton presumably helped Lewis with taxonomy and recommended texts, including his own famed Elements of Botany, which Lewis purchased for six dollars, a high price for a book in those days. Wistar perhaps made suggestions about fossils, a field in which he was skilled, but since neither man's offerings were put into writing, this is mostly guesswork. Nor is it written anywhere that Lewis visited, for purposes of study, Charles Willson Peale's natural history museum, the first of its kind in the United States and located, at that time, in Independence Hall, but it would be most uncharacteristic if he had overlooked the opportunity.
In spite of, perhaps because of, his busy days, Lewis enjoyed Philadelphia. He was associated with important men who clearly liked him, and he was in charge of an enterprise whose successful completion conceivably could bring him lasting fame. When night fell, he was able to turn to diversions he had grown accustomed to in Jefferson's household—stimulating company, handsome women, good talk. His guide to Philadelphia's social scene was Mahlon Dickerson, an entertaining young lawyer and future senator (1817–33) whom he had first met at the White House. They dined together several times, paid calls on various young ladies, and were guests two or three times at the home of Thomas McKean, governor of Pennsylvania. There Lewis again encountered McKean's handsome, curly-haired son-in-law, the Marqués de Casa Yrujo, Spain's minister to the United States. 
Undoubtedly Lewis learned that largely through Yrujo's efforts the right of shippers to deposit their cargoes at New Orleans, a right whose revocation had helped precipitate the expedition, had been restored. It is less certain whether Yrujo learned from Lewis that the expedition into Upper Louisiana, for which he had refused to grant passports, was going ahead anyway. In time to come the ambassador would object so constantly to Jefferson about his actions concerning Louisiana that the exasperated president would demand his recall.  Affairs had not reached that pass in May, however, and the meetings passed without jangle, though perhaps with cat-and-mouse games for information that Lewis, holding the upper hand, would have enjoyed.
Another satisfaction came from the solution of a nagging problem about transportation. His initial plan had been to launch the expedition from South West Point, Tennessee, close to the Cumberland River, a major tributary of the Ohio. But Congressman William Dickson of Tennessee, whom he had counted on to arrange for a keelboat and pirogue, had not answered his letters, and Major William McRae, who had been delegated to enlist, on approval, personnel for the expedition, wrote that a sufficient number of qualified men could not be found among the riffraff at the Point.
Meanwhile supplies were piling up in Philadelphia—twenty-seven hundred pounds, with another eight hundred or so waiting to be picked up at Harpers Ferry for transport across the mountains. The agent responsible, under government contract, for moving all public freight from the Atlantic to the trans-Appalachian area was one William Linnard. He knew roads, boatyards, and military installations. During discussions about the supplies, Lewis and he decided to switch the expedition's departure point from Tennessee to Pittsburgh, where the Allegheny and Monongahela rivers join to form the Ohio. Lewis ordered a five-horse outfit for the hauling, and dashed off a letter to the boatyard Linnard recommended, specifying the kind of craft he wanted and asking, overoptimistically, that it be ready for departure by July 20. 
By this time he was eager to be on the move. Except for a few more astronomical lessons from Robert Patterson, he had completed what he had been ordered to do, and instructions from Jefferson about the aims of the expedition as a whole were already at hand. Ostensibly a guide for Lewis as he marched west, this remarkable document was also the president's statement to history about the purpose of the quasi-secret, quasi-illegal mission he was about to send on its way. Into it he poured all that had piqued his encyclopedic curiosity during decades of interest in the American West. He did not let the orders rest on his musings alone. Having finished a rough draft, he sent copies to his cabinet members for suggestions.
Only Albert Gallatin and Levi Lincoln, the attorney general, had responded at length. Gallatin, remembering military reconnaisance as the original motive behind the expedition, did not want that element dropped, even though the right of deposit had been restored. The antagonistic nations of Europe still might carry their warfare into the Mississippi Valley. Lewis, therefore, should acquire "a perfect knowledge of the posts, establishments & force kept by Spain in upper Louisiana," and of the trails British traders used in reaching the Missouri. For the day might come when the United States would have to seize the area from its French owners and Spanish caretakers to "prevent G.B. from doing the same." His reasoning? The Missouri country was bound to be settled eventually "by the people of the U. States." It followed that Lewis should determine the area's boundaries, particularly southward toward Spanish New Mexico, and then examine the land not only for military purposes and scientific knowledge but also for its ability to support a large population. Here indeed was the voice of manifest destiny, unnamed yet but ringing clear. 
Levi Lincoln was more concerned with practical politics. Jefferson's opponents, the Federalists, remained "perverse, hostile, and mali[g]nant." To blunt their barbs, which would be especially sharp if the expedition failed, Lewis's instructions should be given, so far as was possible, a high moral tone. He should be advised, for instance, to determine how the Indians' religious and ethical standards could be improved—that is, made more like those of white Protestants. Who could fail to approve of that? Then he added a cautionary note. Meriwether Lewis was inclined to be rash and stubborn. He should be warned that if crises arose along the way, he should retreat rather than charge headlong. 
After incorporating both men's ideas into a new draft, Jefferson sent it to Philadelphia for further comments by Lewis's tutors and by Lewis himself. Reactions were enthusiastic. The only suggestion from any Philadelphian, and that one by implication only, was for the addition of Dr. Rush's queries to the other Indian material.
The primary object of the mission, the president wrote (his instructions are printed in full in appendix I) was to explore the Missouri and any adjoining Pacific stream that offered "direct and practicable communication across the continent for the purpose of commerce." Mapping was to be detailed and exact. To prevent loss of valuable material, copies of the celestial observations were to be entrusted to several trustworthy men; ". . . one of those copies [should] be on the paper of the birch, as less liable to injury from the damp than common paper." (There is no indication that such a copy was made; birch bark was not handy in the regions the men traversed.)
Since another aim of the expedition was to lay the groundwork for a profitable commerce with the Western Indians, Lewis should take pains to learn as much as he could about them—tribal names, vocabularies, populations, tribal boundaries, relations with other groups of Indians, occupations, diseases, life styles, and morals. He should always deal with the natives in a conciliatory manner, assuring them of the desire of the United States "to be neighborly, friendly & useful to them. . . . Confer with them on the points most convenient as mutual emporiums"—by which the president meant government-operated trading factories. He should arrange, if possible, to have influential chiefs visit the United States to see for themselves its power and richness. He should take with him "kine pox," a vaccine for smallpox, a disease to which Native Americans were particularly susceptible, and explain its use. In event of opposition by any "nation" (did Jefferson mean Spain or England as well as Indian tribes?) he must give way. "In the loss of yourselves, we should lose also the information you will have acquired."
Back to commerce: Lewis should investigate the possibility of diverting down the Missouri and into the U.S. the furs currently being sent to the West Coast for barter with ship traders. Most of those fur gatherers were Americans, but a cross-country route would be preferable to the long sea voyages around Cape Horn or the Cape of Good Hope.
And the end was not yet. Lewis was to bring back scientifically oriented reports on the topography, soil, climate, vegetation, animals, and minerals of the land he crossed. He should learn what he could of the southern tributaries of the Missouri and their connection, if any, with the Rio Grande and the Colorado River. He should discover, too, the routes Canadian traders used in reaching the Missouri.
As for getting home again, he should consider retracing his outward path, checking his original observations along the way, but only after sending two couriers East by sea—if a ship turned out to be available. If the outward journey had been "eminently dangerous," all could return by sea, again if a trading ship could be contacted. He would be given open letters of credit with which to buy fresh new clothes for his men and pay for the long ocean voyage. Lastly, after becoming acquainted with his group, he should name the most dependable among them to be his successor in the event of his being incapacitated or dying along the way.
With those awesome charges in mind—the final draft would be drawn up after the last suggestions had been received—Lewis returned to Washington, arriving sometime in early June.  There he learned of astounding news from France, where the American ambassador, Robert Livingston, and Jefferson's special envoy, James Monroe, had been seeking to obtain New Orleans and West Florida from Napoleon. During the talks the Duc de Talleyrand and François de Barbé-Marbois, head of the French treasury, had suddenly asked whether the United States would be interested in acquiring not pieces of Louisiana but all of it.
Napoleon's affairs had come to a crisis. His Santo Domingo adventure, during which his brother-in-law, General Charles Le-clerc, had died of yellow fever, had collapsed. A renewal of war with England was imminent. Finally, Bonaparte wanted to impress history by reforming the unwieldy structure of the French government. Restoring France's New World empire, in short, had become irrelevant, and the first consul was willing to give up the enormous territory he had wrenched from Spain only two and a half years earlier for a mere one hundred and twenty million francs—this despite his promise to Carlos IV that he would never sell the territory, least of all to the United States.
Unable to conceal their astonishment, the American envoys stammered they had no authority to make such a purchase. How sad, Barbé-Marbois murmured to Livingston. For when war broke out, as assuredly it would, British naval forces in the Caribbean most probably would seize New Orleans for their nation, as a step toward Canada and the eventual boxing in of the Americans between the Atlantic and the Mississippi. In order to prevent such a disaster would it not be well to seize the initiative—and quickly, since Napoleon would not wait?
Late in the night of April 12, 1803, Livingston hurried to his desk in the American legation, and, writing feverishly until 3:00 A.M. on the 13th, described the situation in a long dispatch to Secretary of State James Madison. He and Monroe, he said in effect, had no choice but to go ahead with the negotiations, holding the price to as low a figure as they could. 
So affairs stood when Meriwether Lewis reached Washington. Luck again! Pure, shining luck! His expedition, which had been designed to pussyfoot ambiguously around in someone else's territory, showing off its wares to Indians attached commercially to other nations, suddenly was on the edge of achieving real historic status as the first Americans to explore officially the almost totally unknown lands beyond the Mississippi. American lands, for surely Jefferson would not repudiate the negotiations now. The purchase completed, a new gloss would inform every mile Lewis traveled. Every item of knowledge he acquired would be American knowledge, for the use of generations of Americans still to come.
Americans as far west as the Pacific? Why not? Louisiana certainly embraced the headwaters of the Missouri in the north and possibly reached even to the Rio Grande in the south. Territory beyond these limits might well fall into his country's hands through what was sometimes called the principle of contiguity—especially if he and his handful of men found a river that would let them link their overland discoveries to those made eleven years earlier by Robert Gray, when he had sailed his ship into the mouth of the Columbia on May 11, 1792.
Sea to shining sea! And he was on hand with his head crammed with astronomical formulas, his medicine chest with pills, and his packing boxes with Indian goods, ready to make the most of his fortune . . . provided something had not happened in Paris to end the negotiations before the purchase was completed. Suspense gnawed at him. If only transatlantic communications weren't so slow!