Pennsylvania Avenue lighthearted celebrations, including a series of day- and nighttime Shriner's parades in the 1920s and 1930s. Thomas and Concepcion Picciotto are the founders of the White House Peace Vigil, the longest running anti-nuclear peace vigil in the US, at Lafayette Square on the 1600 block of Pennsylvania Avenue. After the Oklahoma City bombing in 1995, the Secret Service closed the portion of Pennsylvania Avenue in front of the White House to all vehicular traffic. Pedestrian and bicycle traffic, however, was still permitted on the sidewalk. After 9/11 this policy was made permanent. Near the White House traffic is redirected to
Constitution Avenue part of the grounds of the President's Park (which includes the White House), also borders the north side of Constitution Avenue NW and forms the boundary between the western and eastern segments of this part of the street. To the east on the north side is Federal Triangle, which contains the headquarters of a number of federal agencies. These include the Department of Commerce, Department of Justice, Environmental Protection Agency, Federal Trade Commission, Internal Revenue Service, and National Archives. The Embassy of Canada and John Marshall Park are located further east of Federal Triangle. Once past Pennsylvania Avenue NW, the