Shearer was born in May Pen, Jamaica, to parents Samuel and Sophie (née Parnell), and raised from infancy in the Harlem area of Manhattan, New York City [REF].
During World War II, Shearer served in the U.S. Army's segregated 92nd Infantry Division, reaching the rank of sergeant,[REF] and earning the Bronze Star for his position as art director for the division's magazine, The Buffalo [REF].