Who Is Our Melville?

Just finished Sean Wilentz's Bob Dylan In America.  It is an interesting analysis of Dylan's mining (borrowing? sampling? plagiarizing?) of American cultural history for use in his art.  And what a culture to mine!  As a Canadian, it makes me wonder who are our Whitman & Twain & Steinbeck?  Although having no event equivalent to the Civil War we did, nonetheless, also settle a west and suffer through World Wars I & II and the Great Depression.  I have some suspects and will now proceed to investigate and report back.