By the early and mid-20th century, the city was in decline as factories became old and obsolete, and businesses moved out of the region for cheaper labor elsewhere. Boston responded by initiating various urban renewal projects under the direction of the Boston Redevelopment Authority (BRA), which was established in 1957. In 1958, BRA initiated a project to improve the historic West End neighborhood. Extensive demolition was met with vociferous public opposition.

During what century did businesses move out of Boston to find cheaper labor?