Lincoln Signs An Act Creating The Idaho Territory

On March 4, 1863, President Lincoln signed an act creating Idaho Territory.

(While the bill was passed on March 3, the enrolled bill was not signed by the speaker of the House and the presiding officer of the Senate until the early hours of March 4—after which Lincoln received the measure for his signature.) Part of the Louisiana Purchase, Captains Meriwether Lewis and William Clark crossed into Idaho at Lemhi Pass in 1805. At that time, approximately 8,000 Native Americans lived in the region. Originally part of the Oregon and Washington territories, fur trading and missionary work attracted the first settlers to the region. More than twenty thousand emigrants passed through southeastern Idaho during the California Gold Rush of 1849.

Idaho, as part of the Oregon Country, was claimed by both the United States and Great Britain until the United States gained undisputed jurisdiction in 1846. From 1843 to 1849 present-day Idaho was under the de facto jurisdiction of the Provisional Government of Oregon.

Between then and the creation of the Idaho Territory in 1863, parts of the present-day state were included in the Oregon, Washington, and Dakota Territories. The new territory included most of present-day Idaho, Montana, and Wyoming. The first organized communities, within the present borders of Idaho, were established in 1860.