John "Jack" Lovell Thomas (28 October 1926 – June 11, 2005) was the George L. Littlefield Professor of American History at Brown University, Rhode Island, USA.
He entered Bowdoin College, Maine in 1944 to study history.
[1] He was awarded the 1964 Bancroft Prize for his biography of William Lloyd Garrison, The Liberator.
His other books include Alternative America and A Country in the Mind.
[2] He benefitted from a Guggenheim Fellowship in 1966 and was a Woodrow Wilson Fellow in 1982.