Page:Geographic Areas Reference Manual (GARM).pdf/34

 Legal entities are the primary component of the Census Bureau’s geographic hierarchy. States, counties, incorporated places, and minor civil divisions (MCDs) have been used in the Census Bureau’s enumerations and data tabulations since the first decennial census of 1790. The U.S. Constitution, Federal legislation, and more recently, Federal court decisions require that the Census Bureau collect and tabulate statistics for these and other legally defined areas.

The Census Bureau’s first and most long-standing obligation has been to provide accurate population counts for each State every ten years. This requirement dates from the founding of the Republic. In 1787, the delegates to the Constitutional Convention included a requirement for a census, and implicitly, census geography, in the Constitution:

Congressional statutes provide the legal basis for the taking of the Federal censuses. The first census law (March 1, 1790) directed the Federal marshals, then in charge of taking the census, to assign to their assistants:

Such geographic divisions were the building blocks for taking the early decennial censuses and for presenting statistical totals for States, counties, MCDs, and incorporated places. The Census Bureau always has devoted much effort to fulfilling this commitment; in fact, one of its major geographic efforts today is the periodic Boundary and Annexation Survey (BAS), by means of which it ascertains the legal boundaries, status, and names of these governmental units.

Federal law still makes provision for the Census Bureau’s data collection activities and, in a general way, for the scope of the Census Bureau’s geographic 2-16Geographic Overview