William Seward received welcome attention from historian Doris Kearns Goodwin in her landmark study of Lincoln and the men he appointed to his cabinet, Team of Rivals. But decades after the last major biography of Seward, the one-time presidential aspirant and Secretary of State deserved another thorough examination, which Walter Stahr offers in Seward: Lincoln’s Indispensable Man (Simon & Schuster, $32.50). Stahr, who had a career in law and finance before turning full time to writing biographies (his first book was about another behind-the-scenes power, John Jay), unearthed a trove of documents that enabled him to challenge some of the conventional wisdom about Seward’s role in several of Lincoln’s most important decisions regarding treatment of the South during the Civil War—and more.