Robert Lowell was regarded by many as the greatest American poet of his generation. "Somehow or other...in the middle of our worst century so far," his contemporary and friend Elizabeth Bishop wrote, "we have produced a magnificent poet." The scion of a distinguished New England family, Lowell crafted his poetry to comment on the nation's fate and even to influence the course of American politics. Along with Anne Sexton, John Berryman, and Sylvia...