If the family was in IT [Indian TERR.] during 1870 & 1880 they will not be counter.
General Information – 1870 census Four new states were added to the Union between 1860 and 1870 for a total of 37 states: Kansas, West Virginia, Nevada and Nebraska. In addition, six new territories were created: Dakota Territory, Colorado Territory, Arizona Territory, Idaho Territory, Montana Territory and Wyoming Territory. The Unorganized Territory, unofficially called the "Indian Territory" was not enumerated for non-Indians in 1870.
General Information – 1880 census Colorado was the only state admitted to the Union between 1870 and 1880, bringing the total to 38 states. Eight territories were enumerated: Arizona, Dakota, Idaho, Montana, New Mexico, Utah, Washington and Wyoming territories. Unorganized Alaska was enumerated, but the "Indian Territory" was not enumerated for non-Indians. Unlike any previous censuses, after microfilming, the original 1880 census schedules for several states were transferred from the National Archives to various state archives, state libraries, or universities libraries. Only the original 1880 schedules for Pennsylvania remain at the National Archives. Several originals were later transferred to the National Society Daughters of the American Revolution in Washington, D.C.