Jimmy Hoffa IBT would expand as the union itself grew. Hoffa worked to defend the Teamsters unions from raids by other unions, including the CIO, and extended the Teamsters' influence in the Midwestern states, from the late 1930s to the late 1940s. Although he never actually worked as a truck driver, he became president of Local 299 in December 1946. He then rose to lead the combined group of Detroit-area locals shortly afterwards, and advanced to become head of the Michigan Teamsters groups sometime later. During this time, Hoffa obtained a deferment from military service in World War II by successfully making
Jimmy Hoffa caused by the 1975 disappearance of her husband, because her health had declined steadily since then. She is entombed in Michigan. In 1989, Kenneth Walton, the head of the FBI's Detroit office, told "The Detroit News" that he knew what happened to Hoffa. "I'm comfortable I know who did it, but it's never going to be prosecuted because ... we would have to divulge informants, confidential sources." In 2001, the FBI matched DNA from Hoffa's hair—taken from a brush—with a strand of hair found in a 1975 Mercury Marquis Brougham driven by longtime friend Charles "Chuckie" O'Brien on July 30,