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:
“Representatives and direct Taxes shall be apportioned among the several States which may be included within this Union according to their respective Numbers. The actual Enumeration shall be made within three Years after the first Meeting of the Congress of the United States, and within every subsequent Term of ten Years in such Manner as they shall by Law direct.”
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:
“… a certain division of … one or more counties, cities, towns, townships, hundreds, or parishes, or of a territory plainly and distinctly bounded by water courses, mountains, or public roads.”
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
