The Illinois-Wabash Company, more formally known as the United Illinois and Wabash Land Company, was an 18th century land company established to facilitate land speculation and investment in the region that became the Northwest Territory of the United States. The company was formed from the merger of the Illinois Company and the Wabash Company.

The company was organized by Philadelphia financiers to control trade in the region in an attempt to establish a monopoly in competition with other colonial land companies—Ohio Company of Virginia, Indiana Company, Transylvania Company. The Illinois-Wabash Company purchased land in defiance of the British Royal Proclamation of 1763 which prohibited westerward encroachment. This became an issue in 1818 when William McIntosh obtained a land patent from the federal government that had been purchased from Native Americans by William Murray for the Illinois-Wabash Company. Successors to Murray took the case to the U.S. Supreme Court in Johnson v. M'Intosh, which decided in favor of McIntosh and ruled that the U.S. government would not recognize private purchases of native lands.

The assets of the Illinois-Wabash Company comprised land purchased from Native American tribes in 1773 and again in 1775. The company's members and investors were largely from landlocked colonies without room for expansion — namely Maryland and Pennsylvania. Small frontier posts were erected in various parts of the Illinois-Wabash Company land holdings before the American Revolutionary War. The war however doomed the company's prospects when, through the chaos of the Continental Congress' focus on the war effort, Virginia made a blanket claim of the lands the Illinois-Wabash Company had acquired. The action forced the Illinois-Wabash Company to bring forth a case to the Continental Congress to confirm its land holdings.

The case was postponed until the later half of the war and as proceedings for the Articles of Confederation began. Heated and impassioned, leaders from the Illinois-Wabash Company and Virginia argued vehemently for their respective sides over the course of several years. The Continental Congress finally offered a proposal that was agreed upon by the Illinois-Wabash Company, Virginia and all other colonial land companies that had joined the debate. They agreed to cede all western frontier lands to the federal government who would in turn create, settle and administer the lands as the first territories of the newly formed nation.

In 1787, the Northwest Ordinance was enacted with a mandate to form three to five new states. Lands claimed by the Illinois-Wabash Company in present-day Illinois, Minnesota and Wisconsin became part of the larger Northwest Territory which also included the present-day states of Indiana, Michigan and Ohio. In February 1809, the Illinois Territory was established with a promise that if the population rose to 60,000 inhabitants it would achieve statehood. In April 1836, the rest of the Illinois-Wabash Company land holdings became a part of the new Wisconsin Territory.

External links

• History and Interpretation of the Great Case of Johnson v. M'Intosh by Eric Kades
• The Discovery Doctrine, Aboriginal Title, Tribal Sovereignty, and Their Significance to Treaty-Making in the United States by Michael C. Blumm
• text of Supreme Court Johnson v. M’Intosh decision

Early American land companies | History of the Midwestern United States