Southwest Washington is the southwestern quadrant of Washington DC. It is located south of the Capitol Mall and west of South Capitol Street, and it is the smallest quadrant of the city. It was part of Pierre L'Enfant's original city, and, following the American Civil War, it became a working-class neighborhood consisting of Scottish, Irish, German, and Eastern European immigrants to the west of Fourth Street, and freed African-Americans to the east. During the 1950s, the area underwent urban renewal, and the area again underwent revitalization during the 21st century.