Idaho Territory in 1863

Idaho, Montana, and Wyoming territories in 1868

The Idaho Territory was the formal name of the U.S. territory that existed from 1863 to 1890.

The territory was officially organized on March 4, 1863 by Act of Congress, and signed into law by President Abraham Lincoln. It was originally created by areas from existing territories, Most of the area west of the continental divide was formerly part of the Washington Territory, whereas most of the area east of the continental divide had been part of the Dakota Territory.

The first capital was at Lewiston.

In 1864, the Montana Territory was organized from the northeastern section of the territory east of the Bitteroot Range. Most of the southeastern area of the territory was made part of the Dakota Territory.

In 1868, the areas east of the 111th meridian were made part of the newly created Wyoming Territory.

The territory was admitted to the Union as the State of Idaho on July 3, 1890.

External links

• Idaho Governor timeline of events in the Idaho Territory
• Idaho State Univ. document (PDF) on origin of name "Idaho" and how Idaho became territory