Jimmy Hoffa a result of Hoffa's work with other union leaders to consolidate local union trucker groups into regional sections, and then into a national body — work that Hoffa ultimately completed over a period of two decades — membership grew to 170,000 members by 1936. Three years later, there were 420,000. The number grew steadily during World War II and through the post-war boom to top a million members by 1951. The Teamsters organized truck drivers and warehousemen, first throughout the Midwest, then nationwide. Hoffa played a major role in the union's skillful use of "quickie strikes", secondary boycotts, and other
Jimmy Hoffa assaulted. The threats from the mafia that they would get rid of Hoffa were taken very seriously; Hoffa's son is quoted as saying "Dad was pushing so hard to get back in office, I was increasingly afraid that the mob would do something about it." There had been three visits in a short time frame to Hoffa's home at Lake Orion and one trip to the Guardian Building law offices by Anthony Giacalone, an alleged kingpin in the Detroit Mafia, and his younger brother, Vito. Friendly with Provenzano and believed to be related to him, their avowed purpose in coming