Instead of a complete biography of FDR, Alter, a Newsweek columnist, has written a slimmer volume focusing on Roosevelt's "defining moment," the first hundred days of his presidency in 1933 that put the New Deal in place. Things were so bad at the height of the Great Depression that the best minds believed democracy had failed. Alter makes a convincing case that FDR saved democracy with the New Deal. He may well have also saved Europe from the Nazis. One man, in the right place, at the right time, can make a difference. Worth reading concurrently: Phillip K. Dick's The Man In The High Castle - a fantasy novel that begins with the premise that Roosevelt was assassinated by Giuseppe Zangara days before taking office (it very nearly happened), the US lost the war, and the Nazis and Japanese run the world. It takes place in 1962, after the Nazis have drained the Mediterranean, razed Africa, and split the US down the middle with the Japanese. What might have been had Roosevelt failed.