 thumb|right|200px|northwest territory of the united states, 1787 thumb|right|200px  an organic act, in united states law, is an act of the united states congress that establishes a territory of the united states or an agency to manage certain federal lands. the first such act was the northwest ordinance, passed in 1787 by the u.s. congress of the confederation (under the articles of confederation, predecessor of the united states constitution). the northwest ordinance created the northwest territory in the land west of pennsylvania and northwest of the ohio river and set the pattern of development that was followed for all subsequent territories. the northwest territory covered more than 260,000 square miles and included all of the modern states of ohio, indiana, illinois, michigan, wisconsin, and the northeastern part of minnesota. the district of columbia organic act of 1801 incorporated washington, d.c. and placed it under the exclusive control of the united states congress. the organic act for the territory of new mexico was part of the compromise of 1850, passed september 9, 1850. primarily concerned with slavery, the act organized new mexico as a territory, with boundaries including the areas now embraced in new mexico, arizona, and southern colorado. ==list of organic acts== later organic acts have included (in chronological order): areas now part of a u.s. state or d.c.: * the northwest ordinance * the indiana territory, that had been part of the northwest, and endured from 1800 until the formation in 1816 of the state of indiana * the district of columbia organic act of 1801 * the organic act of 1804, with respect to the territory of orleans * the michigan territory, partitioned from the ohio in 1806 * the illinois territory, partitioned from the indiana in 1809 * the organic act of 1848, created the territory of oregon * the utah territory, created in 1850 after entry to possession dictated by the 1848 treaty of guadalupe hidalgo * the new mexico territory, ibid * the kansas territory, formed in 1854 by the kansas-nebraska act * the nebraska territory, ibid * the colorado organic act, partitioned the territory of colorado in 1861 from the kansas territory, as well as some of the southwestern nebraska territory, and a small parcel of the northeastern new mexico territory. * the nevada territory, partitioned from the utah territory in 1861 * the dakota organic act of 1861 * the [[
United_States_federal_legislation United_States_federal_territory_and_statehood_legislation