The Northwest Territory was a general term used during the post-Revolutionary War period of American history referring to the area bounded between the Pennsylvania border to the East, Ohio River to the South, Mississippi River to the West and somewhat variable Canadian border (or otherwise the Great Lakes) to the North.

The region owes its existence in an independent form firstly to Maryland. When the Articles of Confederation were first being drawn up, a last hinging point preventing unanimous approval was the inordinate amount of land states such as New York and Virgina had compared to other, smaller states. Their claims extended as far as the Pacific Ocean, an anachronistic leftover from the days of colonization. Though other smaller states were appeased, Maryland held out stubbornly, preventing the Confederation from becoming a reality, unless the issue was amended. New York finally gave in, which put pressure on Massachusetts and Connecticut to toe the line as well. Of these cessions, the Northwest Territory was formed.

Though now merely forming one half of the rather overlooked Midwestern states: Wisconsin, Michigan, Illinois, Ohio, and Indiana, this area does have extremely important historic significance for the expansion of the United States. In order to deal with issues of increased settlement and clamour for the rights of statehood, the Continental Congress made one of its few effective and farsighted moves, drafting the Northwest Ordinance.
