The present state of Colorado became part of the United States in 1848, and the first town, San Luis, was established in 1851. Colorado became a Territory in 1861 and a State in 1876. There is a census of sorts for 1850. In 1860, Colorado was a part of Kansas, lumped together as Araphoe County, Kansas. In 1870 there was a Territorial Census. From 1880 on there was a Federal Census taken for the State.