Final answer:
As of the latest information available, there is one African American U.S Senator serving. Historical figures like Hiram Revels and the growing Congressional Black Caucus mark the progress of African American political representation.
Step-by-step explanation:
As of my knowledge cutoff in 2023, there is one African American U.S Senator serving in the Senate. The historical significance of African American participation in the U.S. Congress goes back to the 1870s, in which Hiram Revels and Blanche K. Bruce served as senators, reflecting a period when African Americans began holding political office. Additionally, political representation for African Americans has been evolving, with the Congressional Black Caucus growing since its inception in 1971 to include fifty-seven members.
According to data, there often has been an underrepresentation of African Americans in Congress when compared to their proportion in the general population. For example, if African Americans were represented proportionally to their numbers in 2009, there should be 12 senators and 52 members of the House. However, there was only one African American senator at that time.