The United States acquired the area of Washington through a treaty with Great Britain in 1846. Washington Territory was organized from part of Oregon Territory on March 2, 1853; it included all of present-day Washington, northern Idaho, and northwestern Montana. In 1859, when Oregon was admitted as a state, the remainder of Oregon Territory the rest of Idaho, additional area of Montana, and part of Wyoming was added to Washington Territory. Washington Territory assumed generally the same boundary as the present state when Idaho Territory was organized in 1863. Washington was admitted to the Union on November 11, 1889, as the 42nd state.
Although the territory had not yet been legally established, census data for Washington are available beginning with the 1850 census. The 1850 and 1860 populations are for the entire territory as legally established in 1859, when it included all of Idaho and part of Montana and Wyoming. The population of the entire legally established Oregon Territory (of which the area of Washington was a part) in 1850 was 13,294.
Data for the legally established state of Washington are available beginning with the 1890 census.
See: Geographic Terms & Concepts
Counties & County Equivalents
Interactive Map of Washington Counties | Static Overview Map of Washington Counties
There are 39 counties in Washington. All counties are functioning governmental units, each governed by a board of county commissioners except for Clallam, King, Pierce, Snohomish, and Whatcom Counties which are each governed by a county council. Six counties, Clallam, King, Pierce, San Juan, Snohomish, and Whatcom, have Home Rule Charters, which among other things, give the counties broad planning powers.
There are 242 county subdivisions in Washington. They are all census county divisions (CCDs), which are delineated for statistical purposes, have no legal function, and are not governmental units.
Places (Incorporated Cities, Towns & Census Designated Places (CDPs))
Washington has 628 places, 281 incorporated places and 347 census designated places (CDPs). The incorporated places consist of 208 cities and 73 towns. A minimum population of 3,000 is required for incorporation if the new entity is within 5 air miles of the boundary of a city with a population of 15,000 or more.
Alphabetical List of Cities, Towns, CDPs and Other Populated Places
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q, R | S | T | U, V | W, X, Y, Z
Washington Civil Features
Washington Civil Features: Political Subdivisions, Native Areas, Land Grants, etc. - sorted by Census Class Codes.
Metropolitan and Micropolitan Statistical Areas
There are 11 Metropolitan and 9 Micropolitan Statistical Areas in Washington. WA Metopolitan & Micropolitan Areas
Washington ZIP Code Tabulation Areas
There are 598 ZIP Code tabulation areas (ZCTAs) in Washington. View Washington ZIP Codes and ZIP Code Maps.
Washington has 295 unified school districts. View Washington Public and Private Schools.
Washington has 10 congressional districts. An interactive map shows the contact information for each Representative as well as the boundaries for each Washington district. View Map of Washington Congressional Districts.
State Legislative Districts
There are 49 state senate districts and 49 state house districts in Washington.
American Indian Areas
Washington has 27 federally recognized American Indian reservations, 15 with off-reservation trust land. There is also one tribal designated statistical area (TDSA).