In 1957, Washington became the first major city in the nation with a majority African-American population. Like many cities, it had received thousands of black people from the South in the Great Migration, starting during World War I and accelerating in the 1940s and 1950s. With the buildup of government and defense industries during World War II, many new residents found jobs. In the postwar years, whites who were better established economically began to move to newer housing in adjoining states in the suburbanization movement that occurred around most major cities. They were aided by the extensive highway construction undertaken by federal and state governments.