This is an east–west longitudinal depression that has been eroded on a belt of relatively weak strata between the resistant crystalline rocks of the Adirondacks on the north and the northern escarpment of the Appalachian Plateau (Catskills-Helderbergs) on the south.

In Wisconsin, the inner lowland is a knob of resistant quartzites, known as Baraboo Ridge, rising from the buried upland floor through the partly denuded cover of lower Palaeozoic strata.

The Ontarian River that was a precursor to Lake Ontario is thought to have drained westward, and the St. Lawrence drainage to have been created by subsidence due to the weight of the ice sheet.

A century and a half of naval and land wars among France, The Netherlands and Britain resulted finally in British control of the region, from the Ohio River to the Arctic, and from the Atlantic to the Mississippi.

Indian Reserve is the historical term for this largely uncolonized area set aside in the Royal Proclamation of 1763[4] for use by Native Americans, who already inhabited it.

[5] The British government had contemplated establishing an Indian barrier state in the portion of the reserve west of the Appalachian Mountains, and bounded by the Ohio and Mississippi rivers and the Great Lakes.

Hoping for favorable claims of territorial control in an eventual peace treaty with Britain, American adventurers led by Kentucky militia leader George Rogers Clark briefly occupied village settlements, including Cahokia, Kaskaskia and Vincennes unopposed, with passive support from Francophone inhabitants.

In the Peace of Paris (1784) Britain ceded what became known as the Northwest Territory, the area bounded by Great Lakes, Mississippi and Ohio rivers, and the eastern colonies of New York and Pennsylvania, to the fledgling United States.

Britain, which may have entertained ambitions to repossess the area if America failed to govern it, retained control over its forts and licensed fur trade for fifteen years.

The ordinance, adopted in its final form just before the writing of the United States Constitution, was a sweeping, visionary proposal to create what was at the time a radical experiment in democratic governance and economy.

The Northwest Ordinance of 1787 prohibited slavery, restricted primogeniture, mandated universal public education, provided for affordable farm land to people who settled and improved it, and required peaceful, lawful treatment of the Indian population.

Civil rights included freedom from cruel and unusual punishment, trial by jury, and exemption from unreasonable search and seizure.

The northeastern section of Minnesota, from the Mississippi to St. Croix River, also fell under ordinance jurisdiction and extended the constitution and culture of the Old Northwest to the Dakotas.

Settlement and economic expansion on both sides accelerated after the 1825 opening of The Erie Canal, an astonishingly successful public venture that effectively integrated markets and commerce between the Atlantic seaboard and the region.

Owner-operator family farms transformed both demographics and ecology into a vast terrain of farmlands, producing primarily wheat and corn.

The region's alliance of antislavery with free soil movements contributed troops and agricultural goods that proved critical in the Union's victory.

The British-Canadian London Conference of 1866, and subsequent Constitution Act of 1867 analogously derived from political, and some military, turmoil in the former jurisdiction of Upper Canada, which was renamed and organized in the new dominion as the province of Ontario.

Nineteenth-century monopolies such as International Harvester, Standard Oil, and United States Steel established the pattern of American centralized industrial consolidation and eventual global dominance.

The region hosted the world's greatest concentrations of production for oil, coal, steel, automobiles, synthetic rubber, agricultural machinery, and heavy transport equipment.

German-born Pennsylvania immigrant John A. Roebling invented steel wire rope, a pivotal part of suspension bridges he designed and whose construction he supervised in Pittsburgh, Cincinnati and Buffalo, based on earlier successful canal aqueducts.

Contributions to modern transportation include the Wright brothers' early airplanes, designed and perfected in their Dayton, Ohio mechanics' workshops; distinctive Great Lakes freighters, and railroad beds constructed of wooden ties and steel rails.

Fraternal, ethnic, and civic organizations extended cooperatives and supported local ventures from insurance companies to orphanages and hospitals.

In part to balance democratic representation against the economic and political power of these corporations, the region hosted industrial labor organization, consolidated agricultural cooperatives and state educational systems.

The Big Ten Conference memorializes the nation's first region in which every state sponsored major research, technical-agricultural, and teacher-training colleges and universities.

During World War II, the region became the global epicenter of motorized land vehicles, including cars, trucks and jeeps, as well as a major supplier of engine, transmission, and electrical components to the wartime aeronautics industry.

The region is a global leader in advanced manufacturing and research and development, with significant innovations in both production processes and business organization.

Two competing Chicago retailers—Montgomery Ward and Sears Roebuck—developed mass marketing and sales through catalogues, mail-order distribution, and the establishment of their brand names as purveyors of consumer goods.

[9][10][11] According to the Brookings Institution, if it stood alone as a country, the Great Lakes economy would be one of the largest economic units on Earth (with a $6-trillion gross regional product).

Chicago is emerging as the third megacity in the United States, after the New York City and Los Angeles metropolitan areas, with a metro population approaching ten million.

[12] The 2017 Global Financial Centres Index ranked Chicago as the twenty-fourth most competitive city in the world, behind Toronto, also in the Great Lakes region, at seventh.