the 1870 census, except for the boundary separating the Dakotas and the merger of the two territories that formed Oklahoma, the States and territorial boundaries of the conterminous United States were essentially fixed. For convenience, the list refers to the States in terms of their present area and boundaries; except for the original 13, usually that area still was a territory or part of a territory at the time of its first Federal census, sometimes with a different name.
In almost all cases, each State or part of a State (other than the original 13) appeared in at least one decennial enumeration before it achieved statehood. The exception is Texas, which was an independent republic before its admission to the Union in 1845 and first appeared in the 1850 census. The 1880 census marked the first enumeration of Alaska. The 1890 census added the Indian Territory and the Oklahoma Territory (combined in 1907 to form the State of Oklahoma), and also reported data for American Indian reservations in other States and territories. The geographic coverage of the 1900 census, which added Hawaii, encompassed the entire area of the present United States.
The county originated as an administrative unit in England; early settlers brought the concept with them to the colonies. Throughout the colonial period, counties evolved as units of local government or administration. However, their importance varied from region to region in response to different economic, social, and political conditions. Long before the Revolution, three distinct systems had developed:
- In much of New England, the compact pattern of settlement favored the town as the local governing body; the county, a geographic grouping of towns, tended to be a legal entity that existed for judicial rather than general governmental purposes.
- In the South, with its dispersed farms and plantations, the county became the most important unit of local administration; towns (or townships) generally did not develop as local, self-governing units in the New England tradition.
