The Illinois campaign, also known as Clark's Northwestern campaign, was a series of engagements during the American Revolutionary War in which a small force of Virginia militia led by George Rogers Clark seized control of several British outposts in the region northwest of the Ohio River in what is now Illinois and Indiana. The campaign is the best-known action of the western theater of the war and the source of Clark's reputation as an early American military hero.
In July 1778, Clark and his men descended the Ohio River from the Falls of the Ohio, crossed overland to the Mississippi River and took control of Kaskaskia, Cahokia, and several other villages in British territory. Vincennes, on the Wabash River was occupied a few weeks later. The occupation was accomplished without firing a shot because many of the French-speaking inhabitants of the region were sympathetic to the Patriot cause. To counter Clark's advance, Henry Hamilton, the British lieutenant-governor based at Fort Detroit, reoccupied Vincennes with a small force in December 1778. In February 1779, Clark returned to Vincennes in a surprise winter expedition and retook the town, capturing Hamilton in the process. Virginia capitalized on Clark's success by establishing the region as Illinois County. The importance of the Illinois campaign has been the subject of much debate. Because the British ceded the entire area northwest of the Ohio River to the United States in the 1783 Treaty of Paris, some historians have credited Clark's actions with nearly doubling the size of the original Thirteen Colonies. For this reason, Clark was acclaimed "Conqueror of the Northwest", and his Illinois campaign—particularly his surprise march on Vincennes—was greatly celebrated and romanticized.
Background The Illinois Country was a vaguely defined region northwest of the Ohio River which included much of what is now the states of Indiana and Illinois. The area had been a part of the Louisiana district of New France until the end of the French and Indian War when France ceded sovereignty of the region east of the Mississippi to the British in the 1763 Treaty of Paris. In the Quebec Act of 1774, the British officially made the Illinois Country part of the Province of Quebec.Dagenais, "Quebec Act, 1774."
In 1778, the population of the Illinois Country consisted of less than 1,000 people of European descent, mostly French-speaking, and about 600 African-American slaves. Thousands of Native Americans lived in villages concentrated along the Mississippi, Illinois, and Wabash Rivers.Watt, Treaties and Treacheries, 17. British official military presence in the region had been nonexistent after the 70 soldiers based at Kaskaskia's Fort Gage had been ordered east during the 1775 Invasion of Quebec. When the soldiers departed, Philippe-François de Rastel, Sieur de Rocheblave, a resident trader and former French officer, was authorized to administer Kaskaskia.Watt, Treaties and Treacheries, 46. Rocheblave, however, lacked the money, resources, and men needed to administer and protect the settlements in the region.Watt, Treaties and Treacheries, 64.
During the Revolutionary War, the Ohio River marked the border between the Illinois Country and Kentucky, which was then a newly settled area claimed by Virginia. The British originally sought to keep Native Americans out of the war, but in 1777, Lieutenant Governor Hamilton received instructions to recruit and arm Indigenous war parties to raid frontier settlements. These war parties were to be accompanied by British Indian Department officers or volunteers from the Detroit militia so as to prevent atrocities.Watt, Treaties and Treacheries, 98. "From 1777 on," wrote historian Bernard Sheehan, "the line of western settlements was under almost constant assault by white-led raiding parties that had originated at Detroit."Sheehan, "Famous Hair Buyer General", 10.
In 1777, George Rogers Clark was a 25-year-old major in the Kentucky County, Virginia, militia. Clark believed that he could end the raids on Kentucky by capturing the British posts in the Illinois Country and then moving against Detroit. In April 1777, Clark sent two spies to Kaskaskia.James, George Rogers Clark, 69; Butterfield, History of Clark's Conquest, 547. They returned two months later and reported that the fort at Kaskaskia was unguarded, that the French-speaking residents were not greatly attached to the British, and that no one expected an attack. Clark immediately wrote a letter to Governor Patrick Henry of Virginia in which he outlined a plan to capture Kaskaskia.James, George Rogers Clark, 112.
Planning
Because the settlers living in Kentucky lacked the authority, manpower, and supplies to launch the expedition themselves, Clark traveled to Williamsburg in October 1777 via the Wilderness Road to meet with Governor Henry. He was joined by a party of about 100 who were leaving Kentucky due to Indigenous raids.Harrison, War in the West, 15; James, George Rogers Clark, 113–14. Clark presented his plan to Governor Henry on December 10, 1777.Harrison, War in the West, 16; English, Conquest of the Northwest, 88. To maintain secrecy, Clark's proposal was only shared with a small group of influential Virginians, including Thomas Jefferson, George Mason, and George Wythe. Although Henry initially expressed doubts about whether the campaign was feasible, Clark managed to win the confidence of Henry and the others. The plan was approved by the members of the Virginia General Assembly, who were only given vague details about the expedition. Publicly, Clark was authorized to raise men for the defence of Kentucky. In a secret set of instructions from Governor Henry, Clark was instructed to capture Kaskaskia and then proceed as he saw fit.James, George Rogers Clark, 115; Butterfield, History of Clark's Conquest, 77–78.
Governor Henry commissioned Clark as a lieutenant colonel in the Virginia militia and authorized him to raise seven companies, each to contain fifty men.James, George Rogers Clark, 114. This unit, later known as the Illinois Regiment, was a part of Virginia's state forces and not a part of the Continental Army.English, Conquest of the Northwest, 125. The men were enlisted to serve for three months, once they reached Kentucky.Butterfield, History of Clark's Conquest, 77. To maintain secrecy, Clark did not tell any of his recruits that the purpose of the expedition was to invade the Illinois Country. Clark was given £1,200 in Continental currency to purchase supplies.
Clark established his headquarters at Redstone Old Fort on the Monongahela River, while three of Clark's associates from Dunmore's War, Joseph Bowman, Leonard Helm and William Harrod, began recruitment efforts.James, George Rogers Clark, 114–115. Clark commissioned Captain William Bailey Smith as a major,Thwaites, Frontier Defense, 271n26. and gave him £150 to recruit four companies in the Holston River valley and meet Clark at the Falls of the Ohio.Butterfield, History of Clark's Conquest, 87.
Clark was unable to raise all 350 men authorized for the Illinois Regiment. His recruiters had to compete with recruiters from the Continental Army and from other militia units. Some believed that Kentucky was too sparsely inhabited to warrant the diversion of manpower, and recommended that it should be evacuated rather than defended.Butterfield, History of Clark's Conquest, 88–89. Settlers in the Holston valley were more concerned with the Cherokee to the south than with the Indigenous tribes north of the Ohio.Harrison, War in the West, 19. A longstanding boundary dispute between Pennsylvania and Virginia meant that few Pennsylvanians volunteered for what was perceived as a campaign to protect Virginia territory, although some did enlist.Harrison, War in the West, 19; James, George Rogers Clark, 115.
Clark's journey down the Ohio
After repeated delays to allow time for more men to join, Clark left Redstone by boat on May 12, 1778, with about 150 recruits, organized in three companies under captains Bowman, Helm, and Harrod. Clark expected to rendezvous with 200 Holston men under Major Smith at the Falls of the Ohio. Traveling with Clark were about 20 families who were going to Kentucky to settle.Butterfield, History of Clark's Conquest, 90; James, George Rogers Clark, 115.
Clark and his men picked up additional supplies at Fort Pitt and at Henry that were provided by Brigadier General Edward Hand, the Continental Army Western Department commander.James, George Rogers Clark, 115–16; Butterfield, History of Clark's Conquest, 91. They reached Fort Randolph soon after it had been besieged by an Indigenous war party. The fort commander asked for assistance in pursuing the raiders, but Clark declined, believing that he could not spare the time.Harrison, War in the West, 20.
Clark stopped at the mouth of the Kentucky River and despatched a message upriver to Major Smith, telling him that it was time to rendezvous. Clark soon learned, however, that of Smith's four promised companies, only one partial company under a Captain Dillard had been raised. Clark therefore sent word to Colonel John Bowman, the senior militia officer in Kentucky, requesting that the colonel send Dillard's men and any other recruits he could find to the Falls of the Ohio.Butterfield, History of Clark's Conquest, 97–98; English, Conquest of the Northwest, 128–129.
Clark's flotilla reached the Falls on May 27. He set up a base camp on a small island in the midst of the rapids, later known as Corn Island. When the additional recruits from Kentucky finally arrived, Clark added 20 of these men to his force, placing them in a company under Captain John Montgomery, and sent the others back to help defend the Kentucky settlements. Clark then revealed to his men that the real purpose of the expedition was to invade the Illinois Country. The news was greeted with enthusiasm by many, but some of the Holston men deserted that night; seven or eight were caught and brought back, but others eluded capture and returned to their homes.James, George Rogers Clark, 116; Butterfield, History of Clark's Conquest, 98–100.
While Clark and his officers drilled the troops in preparation for the Kaskaskia expedition, the families who had traveled with the regiment down the Ohio River settled on the island and planted corn.James, George Rogers Clark, 117. These settlers moved to the mainland the following year, founding the settlement which later became Louisville.Butterfield, History of Clark's Conquest, 135. While on the island, Clark received an important message from Pittsburgh: France had signed a Treaty of Alliance with the United States. Clark hoped that this information would be useful in securing the allegiance of the French-speaking inhabitants of the Illinois country.James, George Rogers Clark, 117; Butterfield, History of Clark's Conquest, 101–102.
Occupation of the Illinois Country
Clark set off from Corn Island on June 24, 1778. The date of departure is sometimes given as June 26, based on a letter Clark wrote to George Mason, but Clark corrected the date in his memoir, since they left the same day as a solar eclipse. Clark left behind seven soldiers who were deemed not hardy enough for the journey. These men stayed with the families on the island and guarded the provisions stored there.Butterfield, History of Clark's Conquest, 104. Clark's force numbered about 175 men in total, organized in four companies under Captains Bowman, Helm, Harrod, and Montgomery.