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. 
In addition to major, national- and international-level firsts, African-Americans have achieved firsts on a statewide basis.
First elected African-American lieutenant governor: Oscar Dunn, Lieutenant Governor of Louisiana
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 Speaker of the Mississippi House of Representatives, and of any state legislature: John R. Lynch
First African American elected to the Indiana general assembly: James Sidney Hinton. 
First African American elected to political office on the West Coast: Frederick Madison Roberts, California State Assembly
First African Americans elected as judges in the state of New York: James S. Watson and Charles E. Toney
First African-American attorney general of Massachusetts: Edward Brooke. Also first African American to hold Massachusetts statewide office, and first African-American attorney general of any state.
First African American woman Texas state senator: Barbara Jordan
First African American appointed to New York State Board of Regents: Kenneth Bancroft Clark
First African American senator from Massachusetts: Edward Brooke. (Also first post-Reconstruction African American elected to the U.S. Senate and first African American elected to the U.S. Senate by popular vote).
First African-American woman admitted to the Mississippi Bar: