Greenwood is a historic freedom colony in Tulsa, Oklahoma. As one of the most prominent concentrations of African-American businesses in the United States during the early 20th century, it was popularly known as America's "Black Wall Street". It was burned to the ground in the Tulsa race massacre of 1921, in which a local white mob gathered and attacked the area. Between 75 and 300 Americans were killed, hundreds more were injured, and the homes of 5000 were destroyed, leaving them homeless. The massacre was one of the largest in the history of U.S. race relations, destroying the once-thriving Greenwood community. Within ten years of the massacre, surviving residents who chose to remain in Tulsa rebuilt much of the district. They accomplished this despite the opposition of many white Tulsa political and business leaders and punitive rezoning laws enacted to prevent reconstruction. It continued as a vital black community until segregation was overturned by the federal government during the 1950s and 1960s. Desegregation encouraged black citizens to live and shop elsewhere in the city, causing Greenwood to lose much of its original vitality. Since then, city leaders have attempted to encourage other economic development activity nearby.