Wyoming. The Territory of Wyoming was an organized incorporated territory of the United States that existed from July 25, 1868, until July 10, 1890, when it was admitted to the Union as the State of Wyoming. Cheyenne was the territorial capital. The boundaries of the Wyoming Territory were identical to the modern State of Wyoming. Because of Wyoming's location as part of the Louisiana Purchase, the Oregon Country, and the Mexican Cession, the land which became Wyoming has a complicated history of territorial relationships. Portions of the territory, which eventually fell under Wyoming's jurisdiction, were at various points associated with the territories of Washington, Oregon, Idaho, Dakota, Nebraska, and Utah, and had previously belonged to the independent states of Great Britain, France, Spain, Mexico, and Texas. The portion of the Wyoming Territory east of the continental divide was acquired by the U.S. in the 1803 Louisiana Purchase and organized into the Nebraska Territory in 1854. On March 2, 1861, the northern portion of the Nebraska Territory, including the northeastern portion of future Wyoming Territory, became part of the Dakota Territory, while the southeastern portion remained with Nebraska, forming an extended Nebraska panhandle which included the settlement of Cheyenne. In 1863, the Idaho Territory was formed; it included the entirety of the modern states of Idaho and Montana and almost all of modern Wyoming save the southwest corner.