Long was born in Baltimore, Maryland. He performed in a number of Broadway shows, including Black Rhythm (1939), Porgy and Bess(as Sportin' Life in the 1942 revival), and Beggar's Holiday (1946). Long and Lena Horne co-introduced the Harold Arlen-Ted Koehler composition "As Long As I Live" in "Cotton Club Parade" (1934) when Miss Horne was only 16 years old.
He reprised his role of Sportin' Life in the 1951 3-LP Columbia Masterworks recording of Porgy and Bess, the most complete recording of the opera issued up to that time. He also co-starred with Thelma Carpenter in the 1952 revival of Shuffle Along, which they recorded for RCA Victor.
Long received a Tony Award nomination for Best Supporting or Featured Actor (Musical) in 1973, for the role of Dave in Don't Play Us Cheap. The all-black play opened at the Ethel Barrymore Theater in New York on May 16, 1972 and ran for 164 performances. Long, along with Thomas Anderson, Joshie Armstead, Robert Dunn, Jay Van Leer, Esther Rolle, Mabel King, George Ooppee McCurn, Frank Carey, Nate Barnett, and Rhetta Hughes, recreated their stage roles in a film production by Melvin Van Peebles, in 1973.
He originated the role of John in Bubbling Brown Sugar on Broadway, which opened at the August Wilson Theatre (then-ANTA Playhouse) on March 2, 1976, and closed on December 31, 1977, after 766 performances.
Long also appeared in a number of films and television shows. He played the elderly Chicken George Moore in Roots: The Next Generations miniseries, and had small roles in Trading Places - memorable as Ezra, the man to whom Don Ameche gives a miserably small Christmas bonus ("maybe I'll go to the movies - by myself"), The Sting, and Harry and Tonto.
Long died from cancer at 73, on February 15, 1984 in New York City, and was interred in NY's Ferncliff Cemetery, in Hartsdale, New York.
His oldest granddaughter is author, artist and radio talk show host JoAnn Pinkney Wilcox, who wrote the book "Getting Paid To Keep You In Debt!"