The distance across country, from Kaskaskia to Vincennes, is about two hundred thirty miles. In summer it was a delightful region of alternating groves and prairies; in the dead of winter, it would afford fair traveling over the frozen plains and ice-bound rivers; but now, in February (1779), the weather had moderated, and great freshets had flooded the lowlands and meadows. The ground was boggy, and progress was slow and difficult; there were no tents, and the floods had driven away much of the game; and Clark and his officers were often taxed to their wits' ends to devise methods for keeping their hard-worked men in good spirits. Often they were obliged to wade in the icy water, for miles together, and to sleep at night in soaked clothes upon little brush-strewn hillocks, shivering with cold, and without food or fire.
But at last, after nearly three weeks of almost superhuman exertion and indescribable misery, Vincennes was reached. The British garrison was taken by surprise, but held out with obstinacy, and throughout the long moonlight night the battle raged with much fury. The log fort was on the top of a hill overlooking the little town; it was armed with several small cannon, but Clark's men had only their muskets. They were, however, served freely with ammunition by the French villagers; and, being expert marksmen, could hit the gunners by firing through the loopholes, so that by sunrise the garrison was sadly crippled. The fight continued throughout the following morning, and in the afternoon the British ran up the white flag. Hamilton and twenty-six of his fellows were sent as prisoners overland to Virginia.
Clark remained as master of the Northwest until the close of the Revolutionary War. The fact that the flag of the republic waved over Vincennes, Kaskaskia, and Cahokia when the war ended, had much to do with the decision of the peace commissioners to allow the United States to retain the country lying between the Ohio and Mississippi rivers and the Great Lakes.
During the Revolution, none of the forts in Wisconsin were occupied by British soldiers, and they were allowed to tumble into decay. Wisconsin was, however, used as a recruiting ground for Indian allies. Not only did Langlade and Gautier raise a war party of Wisconsin Indians to help Hamilton in his expedition against Vincennes, but they were frequently in Wisconsin on similar business during the war. In 1779 Gautier led a party of Wisconsin Indians to Peoria, in the Illinois country, where there was an old French fort which, it was thought, might fall into the hands of the Americans. Gautier burned this fort, and then hastily retreated because he found that Clark was making friends with all the Illinois Indians.
Clark's agents traded as far north as Portage, in Wisconsin. At Prairie du Chien they induced Linctot, a famous French fur trader, to join the Americans. Linctot put himself at the head of a party of five hundred French and half-breed horsemen, who were of much assistance to Clark in his various movements after the capture of Vincennes. Meanwhile another large party, chiefly of Indians, assembled at Prairie du Chien in the British cause, led by three French traders, Hesse, Du Charme, and Calvé. They raided the upper Mississippi valley, capturing provisions intended for the Americans, and making a futile attack on the Spanish village of St. Louis, which was thought to be assisting Clark.
Despite these military operations in Wisconsin, the English fur trade continued in full strength, with headquarters upon the Island of Mackinac, but with French agents and boatmen, whose principal dwelling places were at Green Bay and Prairie du Chien. Upon Lake Superior large canoes and bateaux were used; but upon Lake Michigan were three small sloops, the Welcome, the Felicity, and the Archangel, which carried supplies and furs for the traders, and made frequent cruises to see that the "Bostonians," as the French used to call the Americans, obtained no foothold upon the shore of the lake.
Just before the close of the war, the British commander at Mackinac Island, Captain Patrick Sinclair, held a council with the Indians, and for a small sum purchased for himself their claims to that island and to nearly all of the land now comprising Wisconsin. But the treaty of 1783, between the British and the Americans, did not recognize this purchase, and Sinclair found that he was no longer the owner of Wisconsin. It had become, largely through the valor of Clark, and the persistence of our treaty commissioners, a part of the territory of the United States.