Alexander Calder is one of the most beloved and widely admired artists of the twentieth century. Anybody who has ever set foot in a museum knows him as the inventor of the mobile, America's unique contribution to modern art. But only now, forty years after the artist's death, is the full story of his life being told in this biography, which is based on unprecedented access to Calder's letters and papers as well as scores of interviews. Jed Perl shows us why Calder was--and remains--a barrier breaker, an avant-garde artist with mass appeal.