Jefferson Territory was the name proposed in 1859 for the area that covered the present state of Colorado and large parts of what are now Nebraska, Utah, and Wyoming. Thousands of Americans rushed into the Rocky Mountain region of Colorado in 1858 and 1859 because of rumors and reports of gold discoveries. In 1859, residents established a provisional government and elected Robert W. Steele as governor. They also asked Congress for recognition as the Jefferson Territory. But Congress failed to grant the request, partly because its members were involved in a bitter dispute over the spread of slavery to new territories. The provisional government continued to operate until 1860. In 1861, after seven Southern states withdrew from the Union over the slavery issue, Congress made the former Jefferson Territory the Colorado Territory (see Colorado (The gold rush) ).
