The airport is really convenient for the city. It is on the blue and yellow metro lines – and is only a short distance from the Capital (3 miles away). On my 25 mile walk from Mount Vernon to the Senate last year, we walked on the Mount Vernon Trail through the grounds of the airport. Many members of Congress use the airport to travel between Washington and their home districts.
Construction began in 1940, after President Roosevelt made a recess appropriation of $15 million to build a new Airport by reallocating funds from other purposes. Some of the original buildings can still be seen. (The terminal itself is modern).
Information about the airport can be found here.