Etymology

The Washington Territory was named after George Washington, the first President of the United States. The area was originally part of a region called the Columbia District after the Columbia River. The area was renamed Washington in order to avoid confusion with the District of Columbia, which contains the city of Washington.^[3][4]
Washington is the only U.S. state named after a president. To distinguish it from the U.S. capital, which is also named for George Washington, Washington is sometimes referred to as "Washington State", or, in more formal contexts, as "the State of Washington". Washingtonians and other residents of the Pacific Northwest refer to the state simply as "Washington", calling the nation's capital "Washington, D.C." or, often, simply "D.C.".