McKinley Morganfield was a Starfleet officer active in the 23rd century. (Star Trek: Avenger: "Around the Avenger in Eighty Minutes")
Born in 2257, Morganfield served as a communications officer (specializing in cryptology) on USS Avenger beginning in 2293.
Family
A cousin with the same name — they are named after the 20th century blues singer better known as Muddy Waters — will be born in 2266 and also join Starfleet, which will lead to some confusion in later years.