Montana Territory
The Territory of Montana was an organized incorporated territory of the United States that existed from May 26, 1864,[1] until November 8, 1889, when it was admitted as the 41st state in the Union as the state of Montana.
For the film, see Montana Territory (film).Territory of Montana
Bannack (May 28, 1864–February 6, 1865)
Virginia City (February 7, 1865–1875)
Helena (1875–1889)
May 26 1864
November 8 1889
de Lacy's 1865 map of the Montana Territory
de Lacy's 1872 map of the Montana Territory
The Montana Territory was organized out of the existing Idaho Territory by Act of Congress and signed into law by President Abraham Lincoln on May 26, 1864. The areas east of the Continental Divide had been previously part of the Nebraska Territory and Dakota Territory and had been acquired by the United States in the Louisiana Purchase.
The territory also included a portion of the Idaho Territory west of the continental divide and east of the Bitterroot Range, which had been acquired by the United States in the Oregon Treaty, and originally included in the Oregon Territory. The part of the Oregon Territory that became part of Montana had been split off as part of the Washington Territory.
The boundary between the Washington Territory and Dakota Territory was the Continental Divide (as shown on the 1861 map); however, the boundary between the Idaho Territory and the Montana Territory followed the Bitterroot Range north of 46°30′ north (as shown on the 1864 map). This change was due in part to Congress unifying the area with the creation of Idaho Territory in 1863, coupled with the subsequent political maneuvering of Sidney Edgerton, soon to be the first Territorial Governor of Montana, and his allies in the Congress. They successfully implemented the boundary change that won the Flathead and Bitterroot valleys for Montana Territory.[3] The Organic Act of the Territory of Montana[4] defines the boundary as extending from the modern intersection of Montana, Idaho, and Wyoming at:
Upon the establishment of the Wyoming Territory in 1868, an enclave of Dakota Territory known as Lost Dakota was accidentally created. This error was overlooked by the federal government until 1873, when it was annexed and thereby incorporated into Gallatin County, Montana.[5] The Montana Territory was admitted to the Union as the State of Montana on November 8, 1889.