African Americans are a demographic minority in the United States. African-Americans' initial achievements in various fields historically establish a foothold, providing a precedent for more widespread cultural change. The shorthand phrase for this is "breaking the color barrier."
May: First African-American acting governor: Oscar James Dunn of Louisiana from May till August 9, 1871, when sitting Governor Warmoth was incapacitated and chose to recuperate in Mississippi. (See also: Douglas Wilder, 1990)
First African-American police officer in Chicago, Illinois: James L. Shelton.
First African-American governor of Louisiana: P. B. S. Pinchback (Also first in U.S.) (Non-elected; see also Douglas Wilder, 1990)
First African-American female principal in Massachusetts and the Northeast: Maria Louise Baldwin, supervising white faculty and a predominantly white student body at the Agassiz Grammar School in Cambridge (renamed the Maria L. Baldwin School in 2004).