Why does the state Washington and Washington D.C. have the same name?

The state of Washington is named after the first president of the United States- George Washington.

Washington DC ( a city) is the capitol of The United States of America - is also named after him.

DC stands for District of Columbia. Washington DC is on the east coast of the US.

The Washington Monument - also for George Washington, The Lincoln Memorial - for Abraham Lincoln- , The Jefferson Memorial- For Thomas Jefferson, Arlington National Cemetery , Kennedy Center for the Arts- named for John F. Kennedy, The Capitol Building and much more are located in Washington DC.