Blurred Lines: How U.S. History Affected Town Boundaries


From 1946 to 1964, the United States was in a baby boom, marked by the end of World War II when soldiers were coming home and starting families. With the mass exodus of veterans to areas outside of cities, the suburban movement was taking off. Seeing the United States as a more mobile, spread-out being, President Dwight D. Eisenhower championed the national highway system with the Federal-Aid Highway Act in 1956.


While this period exhibited significant growth in the United States in terms of population, it also showed expansion in terms of how the U.S. Census classified these populations because people weren’t staying in concentrated areas.

Changes in Census Divisions
The Census had always made the same classifications for subdivisions of counties in the form of  MCDs (Minor Civil Divisions), or areas created over time by populations of people, but since many southern and western states had few to no subcounty governmental components, MCDs proved to be challenging because boundaries and names were fluid and subject to change.

Also, incorporated places were often divided into unnecessary parts that cluttered the data. Because of this, MCDs in southern and western states proved to be impossible in providing stable comparisons. Upon realizing that America was branching out from urban areas, the Census started to incorporate CCDs (Census County Divisions) in 1950 in order to account for the areas people were settling in that weren’t clearly defined.

If you look both types of census divisions across the United States, you can see that MCDs cover most of the original colonies and midwestern states, while CCDs cover more rural areas like Montana and Wyoming and then-fast-growing areas like California (in 1900, the state had 2 million; in 1950, 10 million).

Image taken from U.S. Census

Image taken from U.S. Census

Compared to MCD boundaries, which are based more on where people have settled in towns and areas, CCDs boundaries are more square and visible, since they were created by the government to account for these “outskirts” areas that didn’t have a clearly defined “town.”

CCD vs. MCD Characteristics

CCDs (Census County Divisions)
MCDs (Minor Civil Divisions)
Exist in 20 statesExist in 29 states, Puerto Rico, and the Island Areas
No legal function, are not governmental unitsMay or may not have legal function and governmental units
Boundaries usually follow visible features, coincide with tract boundariesBoundaries usually reflect incorporated areas
Exist where there are no legally established MCDsExist as census subareas in Alaska and unorganized territories in 9 states
Name is based on place, county, well-known local name for a locationInclude areas designated as barrios, barrios-pueblo, boroughs, charter townships,
commissioner districts, and more

Washington was the first state to utilize CCDs, right in time for the 1950 Census. In the 1950s and ’60s, 19 more states incorporated CCDs.

States with CCDs

Number of CCDs
Number of CCDs
California386New Mexico131
Florida293South Carolina294
Hawaii44Texas 863

In Texas, Round Rock-Georgetown Township, a suburb of Austin, is an example of a CCD.

States with MCDs

Number of MCDs
Number of MCDs
Connecticut169New Hampshire259
District of Columbia1New Jersey887
Illinois1,679New York1,013
Indiana1,008North Carolina1,040
Iowa1,656North Dakota1,806
Maine530Rhode Island39
Maryland298South Dakota1,707
Minnesota2,742West Virginia277

Because it has no primary divisions, District of Columbia is considered to be an equivalent of an MCD. It’s also considered state and county equivalent, as well—the best of all worlds. MCDs can include census subareas, independent places, and unorganized territories.

In Pennsylvania, Penn Hills Township, a suburb of Pittsburgh, is an example of an MCD.
The Bottom Line
Basically, both MCDs and CCDs are sub-units of a county. In the 21 states that don’t have well-defined townships or MCDs, there are CCDs, so while a state can have MCDs or CCDs, it can never have both. Not only does a background on these provide a little Census history, it can also help Niche users navigate the site, answering questions as to what makes one area a township and another not.