A native of
Jersey City, New Jersey, Fleming graduated from
St. Peter's Preparatory School in 1945 and from
Fordham University in 1950, serving a year in the
United States Navy before he started college. While in the navy, he served aboard the . Fleming served as president of the Society of American Historians and the
PEN American Center. Fleming also spent ten years as chairman of the New York American Revolution Round Table and was an Honorary Member of the New York State
Society of the Cincinnati from 1975. He lived in New York with his wife, Alice, a writer of books for young people. Fleming published books about various events and figures of the
Revolutionary era. He also wrote about other periods of American history, and wrote over a dozen well-received novels set against various historical backgrounds. He said, "I never wanted to be an
Irish-American writer, my whole idea was to get across that bridge and be an American writer". Fleming died at his home in
New York City on July 23, 2017, at the age of 90. == Controversy over Haitian History ==