Rogers Clark, a young Virginia militia officer, launched a campaign to seize the sparsely garrisoned Illinois Country from the British. With a company of volunteers, Clark captured Kaskaskia, the chief post in the Illinois Country, on July 4, and later secured the submission of Vincennes. Vincennes was recaptured by General Henry Hamilton, the British commander at Detroit. In February 1779, Clark marched to Vincennes in a surprise winter march and captured Hamilton himself. To American frontiersmen, Hamilton was known as "the Hair-buyer General" because, they believed, he encouraged Indians to kill and scalp American civilians. For this reason, Governor Thomas Jefferson brought Hamilton to Williamsburg, Virginia, to be tried as a war criminal. After British officials threatened to retaliate against American prisoners of war, Jefferson relented, and Hamilton was exchanged for an American prisoner in 1781. Although Clark's forces captured and held outposts in the lower areas of the territory, British forces maintained control of Fort Lernoult (Detroit). 1780 – Major British and Indian offensive Over the next several years of the war, both sides launched raids against each other, usually targeting settlements. In Spring of 1780, British and Native American forces swept across the Midwest to clear the territories of rebels and Spanish forces, attacking St. Louis and Cahokia and Kentucky, but were repulsed in both battles. In St. Louis, the British and Indian force was repulsed by the mixed Spanish and French creole force. Fort San Carlos, a stone tower in modern downtown St Louis, was the center of this defense. Hundreds of Kentucky settlers were killed or captured in Bird's expedition, however, and within months, General George Rogers Clark retaliated by crossing the Ohio River and attacking Shawnee towns along the Mad River, Chillicothe and Piqua. In the Illinois territory, French officer Augustin de La Balme assembled a militia force of French residents in an effort to take Fort Detroit. The force was destroyed in November by the Miami under Chief Little Turtle. At the same time, the nearly abandoned Fort St. Joseph was raided by Americans from Cahokia. On their return trip, however, they were overtaken by British loyalists and Indians near Petit fort. 1781 Spanish Governor Francisco Cruzat, in St. Louis, sent a force of about 140 Spanish soldiers and American Indians under Captain Eugenio Pourré to capture Fort St. Joseph. It was captured and plundered on February 12, 1781. In late 1780, Clark traveled