Photos: The mystery of Jimmy Hoffa

Nearly 40 years after his disappearance, former Teamsters boss Jimmy Hoffa, pictured circa 1955, remains among America's most famous missing persons. Authorities have been searching for the once powerful union boss since he vanished in 1975.

Nearly 40 years after his disappearance, former Teamsters boss Jimmy Hoffa, pictured circa 1955, remains among America's most famous missing persons. Authorities have been searching for the once powerful union boss since he vanished in 1975.