 His many publications won him wide recognition, including the 1972 Frederic C. Melcher Prize for the best book on religion in America, for his "New England Dissent" (1971).McLoughlin was regarded as “one of the country’s most distinguished historians of American religion.”

McLoughlin opposed American involvement in the Vietnam War and was active in the civil rights movement.He was a former chair of the Rhode Island American Civil Liberties Union.