Congress formally created Wyoming Territory on July 25, 1868 out of portions of Dakota, Idaho, and Utah territories, though this event has sometimes been misdated. Wyoming would go on to become the first US territory to grant women full voting rights in 1869, earning its nickname as the Equality State.
In 1868 the railroad, not the settler's wagon, decided where Wyoming would begin. The Union Pacific had pushed across the high plains the year before, and towns such as Cheyenne sprang up almost overnight along its tracks. The land they occupied was governed from far away, most of it nominally part of Dakota Territory, whose capital lay hundreds of miles to the east. Residents petitioned for a government of their own, and Congress obliged with an organic act, signed by President Andrew Johnson, that assembled a new territory from pieces of Dakota, Idaho, and Utah. Its borders ignored rivers and mountain ranges entirely. The territory was drawn as a rectangle bounded only by lines of latitude and longitude, a shape it keeps today.
The name came from the East. Ohio Congressman James Ashley had championed "Wyoming," a word derived from the Lenape language of the Delaware Valley and already attached to the Wyoming Valley of Pennsylvania. It had no connection to the Shoshone, Arapaho, Cheyenne, Lakota, and Crow peoples whose homelands the new boundaries enclosed. Creating the territory on paper also proved quicker than running it. Its first governor, John A. Campbell, did not arrive in Cheyenne to set up a government until 1869, and the 1870 census counted only about 9,000 non-Native residents across nearly 98,000 square miles.
That small, overwhelmingly male population produced the territory's most famous act. In late 1869 the first territorial legislature passed, and Campbell signed, a law granting women the right to vote and to hold office, the first such measure in the United States. Some lawmakers hoped it would draw women and publicity to the frontier; others acted from conviction. Its effects came quickly. In 1870 Esther Hobart Morris of the mining camp of South Pass City became the first woman in the nation to serve as a justice of the peace, and women sat on juries in Laramie. When Wyoming entered the Union as the 44th state in 1890, it insisted on keeping women's suffrage, even though some in Congress objected to it.