The National Mall is an open-area national park in downtown Washington, D.C., the capital of the United States. Officially termed by the National Park Service the National Mall & Memorial Parks, the term commonly includes the areas that are officially part of West Potomac Park and Constitution Gardens to the west, and often is taken to refer to the entire area between the Lincoln Memorial and the Capitol, with the Washington Monument providing a division slightly west of the center. The park receives approximately 24 million visitors each year.
The idea for the National Mall was originally conceived by Pierre Charles L'Enfant in his plans for the city of Washington, D.C., created in 1791. However, his ideas were not realized until the beginning of the 20th century, with the McMillan Commission plan, which was also inspired by the City Beautiful Movement. Among other things, the McMillan plan called for moving the main railroad station from a site on the National Mall to its present location at Union Station.