As a result of migrations of workers from other parts of the United States, particularly the south, Saginaw's African-American population expanded significantly in proportion to those of European ancestry. Attitudes of racism promoted the segregation of African-American residents into concentrated neighborhoods almost exclusively within the city's east side. Mortgage lenders and real estate sales agents enacted redlining tactics to control where African-Americans lived. Gradually most of the east side's white population migrated either to the west side or to adjacent townships. The Saginaw River became seen as a dividing line for segregated racial groups in Saginaw. As a result emphasis of political campaigns have focused on racial tensions, public services, and blight. After the eventual breakdown of institutionally enforced segregation and increased opportunities for African-Americans, however, the west side has become significantly more diverse in its ethnic and racial composition and no longer has almost exclusively white residents.