In 1986, Blum began working as a reporter for the New York Times, where he earned two Pulitzer Prize nominations. Since 1994, Blum has been a contributing editor to Vanity Fair.
Blum has authored nine books. Several of his books were non-fiction bestsellers, including Gangland, and Wanted!,The Gold of Exodus, and An Epic Story of Vengeance, Salvation, and WWII.
A number of Blum's works have been optioned for film. Miramax Films is in the process of making The Brigade into a major motion picture.
Blum's father was an executive at the Kane Miller Corporation, of Tarrytown, New York. His mother worked as a schoolteacher in New York City. For high school, Blum attended the Horace Mann School and acquired his undergraduate degree from Stanford University, where he also receeived his master's in government. In January 1991, he married Jenny Cox from Martinsburg, West Virginia. They currently reside in Sag Harbor, New York and Connecticut.