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
White House Visitors Office 15th Street on Pennsylvania Avenue NW, in the Federal Triangle. Since September 11, 2001, it no longer serves as a starting point for those going on a reserved tour of the White House; however, it does provide a unique visitor experience for those who did not schedule a tour. The themes of the six permanent exhibits are "First Families", "Symbols and Images", "White House Architecture", "White House Interiors", "Working White House", and "Ceremonies and Celebrations". Other exhibits change throughout the year. It houses a small bookstore operated by the White House Historical Association. The Visitors Office is located in the