Despite the American presidency having been tested by several unforeseen and tragic circumstances, the selection of a vice president traditionally has not been given the scrutiny it deserves. In Accidental Presidents, Jared Cohen (The New Digital Age) thoughtfully examines how American history changed each time a vice president ascended due to their predecessor's death. Eight vice presidents--John Tyler, Millard Fillmore, Andrew Johnson, Chester Arthur, Theodore Roosevelt, Calvin Coolidge, Harry Truman and Lyndon Johnson--became president upon such sober occasions.
Cohen argues that Andrew Johnson succeeding Abraham Lincoln was "the biggest catastrophe of the eight," and details how Johnson changed the course of Reconstruction, leading to a 100-year delay in civil rights for African Americans. Cohen views Truman's ascension as the most positive due to his ability quickly to overcome his unpreparedness. (He adds that Truman must bear some blame for being uninformed, noting that before and after Yalta, Truman "made no inquiries, sought out no meetings, and took no proactive steps to better understand the situation he was about to inherit," despite his suspicions that Franklin Roosevelt was dying.)
Other changes in the course of history include Fillmore's signing of the Fugitive Slave Law in 1850 (which Zachary Taylor promised to veto); Theodore Roosevelt's championing of the progressive movement ("Had [William] McKinley survived, progressivism may have taken decades to gain steam."); and LBJ's far more liberal stance than John F. Kennedy's outlook on civil rights and the role of the government.
Accidental Presidents explores each of these pivotal moments and others that highlight the vagaries of history and how its trajectory changed eight times with the cessation of one beating heart. --William H. Firman Jr., presidential historian and writer