Analysis of information sources in references of the Wikipedia article "Dakota Territory" in English language version.
"On February 22, 1889, outgoing President Cleveland signed an omnibus bill that divided the Territory of Dakota in half. The bill also enable the people in the new Territories of North Dakota and South Dakota, as well as the older territories of Montana and Washington, to write state constitutions and elect state governments. The four new states would be admitted into the Union in nine months. This plan cut Democratic New Mexico out of statehood, and split Republican Dakota Territory into two new Republican states. Rather than two new Republican states and two new Democratic states that Congress had considered the previous year, the omnibus bill created three new Republican states and one new Democratic state that Republicans thought they would capture. In their eagerness to admit both Dakotas, Republican congressmen also ignored the uncomfortable fact that much of the land in the anticipated state of South Dakota belonged to the Sioux[permanent dead link]
