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
Pennsylvania Avenue the east side of the White House. Northwest of the White House, Pennsylvania Avenue runs for to its end at M Street NW in Georgetown, just beyond the Pennsylvania Avenue Bridge over Rock Creek. From 1862 to 1962, streetcars ran the length of the avenue from Georgetown to the Anacostia River. Although Pennsylvania Avenue extends six miles (10 km) within Washington, D.C., the expanse between the White House and the Capitol constitutes the ceremonial heart of the nation. Washington called this stretch "most magnificent & most convenient". Laid out by Pierre (Peter) Charles L'Enfant, Pennsylvania Avenue was one of the