Under the Ordinance of 1787, the westward expansion of the nation began in the Old Northwest Territory, where the American Bill of Rights was first nationally recognized, human slavery was prohibited, primogeniture was abolished, and the principle that colonies could become equal in rights with parent states was established. The Treaty of Paris in 1783 provided that the United States’ northwest boundary should extend from the northwest angle of Lake of the Woods to the Mississippi River, and Itasca Lake, discovered by Henry R. Schoolcraft in 1832 as the source of the Mississippi River, lay on this boundary.