Slide 13 of 31
Notes:
In Census geography, we start with the most basic unit, the Census Block. The Census Block on average has about 100 persons in it. In urban areas a Block can be a very small physical area, yet in rural areas Blocks can span hundreds of square miles. Blocks are usually placed into Block Groups which optimally consist of about 1,500 persons, but can max out at 3,000 persons. Moving up the line, several Block Groups usually fit into a Census Tract which optimally consists of 4,000 persons but can range between 1,500 to 8,000 persons.
Continuing up in the Census hierarchy are places , including incorporated places-that is-legally incorporated governmental entities with a mayor and other offices. There are also Census Designated Places (CDPs) that are closely settled, named, unincorporated communities that generally contain a mixture of residential, commercial, and retail areas similar to those found in incorporated places of similar sizes. CDPs do NOT necessarily have to follow minimum or maximum population guidelines.
Minor Civil Divisions (MCDs) or Census County Divisions (CCDs) are used to establish and maintain a set of subcounty units that have stable boundaries and recognizable names. 21 States have CCDs and 28 States have MCDs; they do NOT necessarily have to follow minimum or maximum population guidelines. A CCD usually represents one or more communities, trading centers or, in some instances, major land uses. An MCD is a type of governmental unit that is the primary legal subdivision of a county, created to govern or administer an area rather than a specific population.(ex. Town, Township, District) Many MCDs represent local general-use government units, which makes them required areas for presentation of decennial census data.
