Until which year did this territory created by Northwest Ordinance legally exist?
1803
Title: Northwest Ordinance
Passage: The Northwest Ordinance (formally An Ordinance for the Government of the Territory of the United States, North-West of the River Ohio, and also known as The Ordinance of 1787) was an act of the Congress of the Confederation of the United States (the Confederation Congress), passed July 13, 1787.  The ordinance created the Northwest Territory, the first organized territory of the United States, from lands beyond the Appalachian Mountains, between British North America and the Great Lakes to the north and the Ohio River to the south.  The upper Mississippi River formed the Territory's western boundary.  It was the response to multiple pressures: the westward expansion of American settlers, tense diplomatic relations with Great Britain and Spain, violent confrontations with Native Americans, the weaknesses of the Articles of Confederation, and the empty treasury of the American government.  It was based upon, but more conservative than Thomas Jefferson's proposed ordinance of 1784.  The 1787 law relied on a strong central government, which was assured under the new Constitution that took effect in 1789.  In August 1789, it was replaced by the Northwest Ordinance of 1789, in which the new Congress reaffirmed the Ordinance with slight modifications.
Title: Northwest Territory
Passage: The post-American Revolutionary War Territory Northwest of the River Ohio, more commonly known as the Northwest Territory encompassing most of the pre-war territory of the Ohio Country, parts of Illinois Country, and parts of old French Canada below the Great Lakes was an organized incorporated territory of the United States spanning most or large parts of six eventual U.S. States.  It existed legally from July 13, 1787, until March 1, 1803, when the southeastern portion of the territory was admitted to the Union as the state of Ohio, and the remainder was reorganized by additional legislative actions.
Title: Strader v. Graham
Passage: Strader v. Graham, 51 U.S. 82 (1851), was a case in which the Supreme Court of the United States held that the status of three slaves who went from Kentucky to Indiana and Ohio depended on Kentucky law rather than Ohio law.  The original plaintiff was Christopher Graham, whose three slaves had traveled to Cincinnati, Ohio, aboard a steamboat owned by Jacob Strader and James Gorman and piloted by John Armstrong.  The slaves later escaped to Canada.  The U.S. Supreme Court recognized the authority of the Northwest Ordinance of 1789 over its applicable territories in Strader v. Graham, 51 U.S. 82, 96, 97 (1851), but did not extend the Northwest Ordinance to cover respective states which were later admitted to the Union.
Northwest Ordinance Northwest Territory