In 1910, the population of black residents were 40,000. By 1960, it grew to 813,000, fueled by the Second Great Migration of blacks into the city during World War II to work in the war industries and during the post-war economic expansion. The United States Supreme Court ruled in "Shelley v. Kraemer" in 1948 that racial covenant policies were unconstitutional, yet such practice continued without opposition over the next two decades. During the post-war economic boom, the Chicago Housing Authority (CHA) tried to ease the pressure in the overcrowded ghettos and put public housing sites in less congested areas in the city. The white residents did not take this very well and reacted with violence when black families tried to move into white areas, so city politicians forced the CHA to keep the status quo and develop high rise projects in black neighborhoods. Some of these became notorious failures. As industrial restructuring in the 1950s and later led to massive job losses to the suburbs amidst the white flight, black residents changed from working-class families to poor families on welfare.