Lieutenant Governor Hamilton engages to deliver up to Col. Clarke, Fort Sackville as it is at present with all the stores, ammunition, & provision &c. &c.

"Account of the Expedition of Lieut. Gov. Hamilton," Pioneer Society of the State of Michigan,
Collections and Researches Made by the Michigan Pioneer and Historical Society, Vol. 9, 2nd ed.
(Lansing: Wynkoop Hallenbeck Crawford Company, 1908), page 504.
Pioneering the Upper Midwest, ca. 1820-1910

Clark Statue, Indianapolis, Indiana, 1904.
Touring Turn-of-the-Century America, 1880-1920

On the morning of February 25, 1779, Lieutenant Colonel George Rogers Clark, elder brother of explorer William Clark, accepted British Lt. Gov. Henry Hamilton's unconditional surrender of Fort Sackville at Vincennes, Indiana.

Despite a 1763 prohibition against settlement of Kentucky and points west, hundreds of colonists and their families drifted beyond the Appalachians. With the Revolutionary War under way, these pioneers were vulnerable to attack from both British and Native American forces.

Clark believed Hamilton rewarded Indians for raids on American settlements. With the support of Virginia's Governor, Patrick Henry, Clark marshalled volunteers from among the frontiersmen and successfully attacked British outposts along the Mississippi River.

To capture Fort Sackville, Clark relied on his men's expert marksmanship and a classic military bluff. Although he commanded a mere two hundred buckskin clad pioneers, Clark raised flags enough for a company of 600. Believing himself overwhelmed, Hamilton surrendered and was imprisoned at Williamsburg. The British never regained control of the fort.

Clark's success was noted by Governor Thomas Jefferson, of Virginia, and General George Washington:

Sir: On the 4th Instant I had the Honor to receive your Letter of the 19th of June. Your Excellency will permit me to offer you my sincere congratulations upon your appointment to the Government of Virginia.

I thank you much for the accounts Your Excellency has been pleased to transmit me of the successes of Cols. Clarke and Shelby. They are important and interesting, and do great honor to the Officers and Men engaged in the Enterprises. I hope these successes will be followed by very happy consequences. If Colo Clarke could by any means gain possession of Detroit, it would in all probability effectually secure the friendship or at least the neutrality of most of the Western Indians.

Letter from George Washington to Thomas Jefferson, July 10, 1779.
The George Washington Papers at the Library of Congress

Clark's bold defense of the trans-Appalachian frontier during the Revolution frustrated British attempts to drive Americans out of the region and legitimized American claims to the Northwest Territory—land ceded to the United States by the Treaty of Paris in 1783.

Patrick Henry, photograph of a painting, 1904.
Touring Turn-of-the-Century America, 1880-1920

• The Today in History features on Illinois and Michigan contain more information about settlement of this region.
• Search the full text of Pioneering the Upper Midwest on George Rogers Clark to retrieve over forty documents pertaining to the Colonel including Clark's Commission to a Fox Chief and Colonel Clark's Memorandum to a Winnebago Chief.
• Search the George Washington Papers on George Rogers Clark to retrieve correspondence related to Clark. These include a July 1779 letter from General Washington to Thomas Jefferson; an August 1779 letter, also to Jefferson, discussing the terms of Lt. Governor Hamilton's imprisonment; and a 1781 letter from Washington to Daniel Brodhead.