He was the son of Edward Sumpter and Alice (Rowe) Snow. He graduated from Harvard University, and Boston University, with an M.A.He married Anna-Myrle Haegg, on July 8, 1932, and they had a daughter Dorothy Caroline.

He was a high school teacher in Winthrop, Massachusetts. During World War II, he served with the XII Bomber Command, and he became a first lieutenant. He was a daily columnist at the Patriot Ledger, in Quincy, Massachusetts, from 1957-82.

He is widely known for his stories of pirates and other nautical subjects; he wrote over forty books and many shorter publications. In all, he was the author of more than 100 publications, mainly about New England coastal history.

Mr. Snow was also a major chronicler of New England maritime history. With the publication of The Islands of Boston Harbor in 1935, he became famous as a historian of the New England coast and also as a popular storyteller, lecturer, preservationist, and treasure hunter. Forty years later, he was still publishing.

He is also famous for carrying on the tradition of the "Flying Santa" for over forty years (1936—1980). Every Christmas he would hire a small plane and drop wrapped gifts to the lighthouse keepers and their families.

Many credit him with saving Fort Warren, located on Georges Island in Boston Harbor, in the 1950s.

In August 2000, a plaque was dedicated to Mr. Snow on his beloved Georges Island. A ferry boat has been named for him.

Since 2002, several of his books were released in new editions published by Commonwealth Editions of Beverly, Massachusetts.