States are the primary governmental divisions of the United States. The District of Columbia is treated as a statistical equivalent of a State for census purposes. Statistics for Puerto Rico, the U. In files for Mining, additional codes appear in the state field for offshore areas codes In files for Construction, codes 91 to 94 are used in the state code field to identify census regions. Counties and their equivalents, 3, in all, are the primary political and administrative divisions of States.
These areas are called parishes in Louisiana. In Alaska, 23 boroughs and "census areas" are treated as county equivalents for census purposes. Several cities Baltimore, MD, St. Louis, MO, Carson City, NV, and 41 cities in Virginia are independent of any county organization and, because they constitute primary divisions of their States, are accorded the same treatment as counties in census tabulations.
That part of Yellowstone National Park in Montana is treated as a county equivalent. The District of Columbia has no primary divisions, and the entire area is considered equivalent to a county for statistical purposes. Counties are identified by a 3-digit Federal Information Processing Standards FIPS code, which is sequenced alphabetically within state, except for the independent cities, which follow the listing of counties within state. Incorporated Places -- The Economic Census provides information for legally defined, incorporated municipalities cities, towns, villages, and boroughs with 2, or more inhabitants as of the population census.
Hawaii does not have incorporated places that are recognized for census purposes, so data there are provided for census designated places CDP's with 2, or more inhabitants. All told, data are presented for places in the United States.
Selected Towns and Townships -- Some county subdivisions, such as towns and townships, are not classified as incorporated places for census purposes.
Statistics are presented in the Economic Census for towns in the six New England states, New York, and Wisconsin, and townships in Michigan, Minnesota, New Jersey and Pennsylvania with a census population of 10, or more.
These towns and townships are presented in the same tables as places. The place code is a five-digit FIPS code assigned to places including independent cities in alphabetic sequence within a state. Its use largely replaces that of the 4-digit census place code used in and earlier censuses. All incorporated municipalities with populations of fewer than 2,, town and townships not qualifying as noted above, and the remainders of counties outside places are categorized as "Balance of county" and assigned a place code of "".
Consolidated City - A consolidated city is a unit of local government for which the functions of an incorporated place and its county or minor civil division MCD have merged. The legal aspects of this action may result in both the primary incorporated place and the county or MCD continuing to exist as legal entities, even though the county or MCD performs few or no governmental functions and has few or no elected officials.
Where this occurs, and where one or more other incorporated places in the county or MCD continue to function as separate governments, even though they have been included in the consolidated government, the primary incorporated place is referred to as a "consolidated city.
Consolidated cities appear only in selected files. They appear immediately after the appropriate county data and immediately before the records for the semi-independent places and "consolidated city balance " that comprise them. ZIP Codes do not align with political or administrative boundaries. ZIP Codes frequently cross county, city, and town jurisidctions.
ZIP Codes may also potentially cross state borders. ZIP Codes have the potential to intersect with multiple geographies. The ratio fields describe the percentage of the respective addresses that fall in both that ZIP Code and each county.
As addresses are created or removed, this changes the ratios in the associated geographies. Why is there a large jump in the number of addresses from to ? Many students also use the files.
Skip to main content. When are Crosswalk Files typically posted? Are names for ZIP codes available? Are Crosswalk Files available prior to Q1? Unfortunately, Crosswalk Files are not available prior to Q1. Are annual Crosswalk Files available instead of quarterly? The files are a snapshot in time at the close of a quarter. Do the address ratios change over time?
What type of organizations use the Crosswalk Files? The first 3 digits of a ZIP code determine the central mail processing facility, also called sectional center facility or "sec center", that is used to process and sort mail. All mail with the same first 3 digits is first delivered to the same sec center where it is sorted according to the last 2 digits and distributed to local post offices.
The sec centers are not open to the public and usually do most sorting overnight. As you can see from the map of the first 3 digits of zip codes , the digits after the first are also generally assigned from east to west. In the map, 0 is closer to white and 9 is much more vivid.
It's easy to follow the gradient across each of the zones even though there are a few exceptions such as the southwest tip of Georgia which uses 39XXX like central Mississippi. Despite the fact that ZIP codes seem to be geographic in nature, that wasn't their intended purpose.
They are intended to group mail to allow the USPS to deliver mail more efficiently. Some ZIP codes will span multiple states in order to make mail routing and delivery more efficient. In most cases, addresses in close proximity to each other are grouped in the same ZIP code which gives the appearance that ZIP codes are defined by a clear geographic boundary. However, some ZIP codes have nothing to do with geogaphic areas.
When ZIP codes appear to be geographically grouped, a clear shape cannot always be drawn around the ZIP code because ZIP codes are only assigned to a point of delivery and not the spaces between delivery points. In areas without a regular postal route or no mail delivery, ZIP codes may not be defined or have unclear boundaries. The main issue is discussed above: there simply isn't always a clear geographic boundary for a ZIP code.
The Census Bureau and many other commercial services will try to interpolate the data to create polygons shapes using straight lines to represent the approximate area covered by a ZIP code, but none of these maps are official or entirely accurate. They provide a very close approximation of the area covered by a ZIP code. You can easily notice some of the boundary issues when viewing our maps.
Very rural areas aren't labeled as belonging to a ZIP code such as much of Nevada and Utah where there are few, if any, addresses to deliver mail.
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