Flint's ethnic diversity increased markedly with the labor demands of the auto industry. History of the substantial African-American community is documented well in the papers of Edgar Holt and Olive Beasley in the GHCC. Also of interest are the papers of Peter Jacquette and Roger Townsend and the scrapbooks of the Flint Urban League.
The following books are some of the more useful ones about African Americans in Flint.
The Arab-American community is well documented in two collections, those of Hani Bawardi and Anthony Mansour.
The Jewish community is covered in Nora Faires and Nancy Hanflik's book Jewish Life in the Industrial Promised Land, 1855-2005, while the GHCC has a run of the Jewish community newspaper, the Jewish Reporter.
The GHCC also has microfilm copies of naturalization records of Genesee County, c.1838-1959.
The large migration of whites from the Missouri Bootheel and neighboring Arkansas and Tennessee is discussed in Beynon's seminal article "The Southern White Laborer Migrates to Michigan."