Jimmy Hoffa Agreement. He played a major role in the growth and development of the union, which eventually became the largest (by membership) in the United States with over 2.3 million members at its peak, during his terms as its leader. Hoffa became involved with organized crime from the early years of his Teamsters work, and this connection continued until his disappearance in 1975. He was convicted of jury tampering, attempted bribery and fraud in 1964, in two separate trials. He was imprisoned in 1967 and sentenced to 13 years. In mid-1971, he resigned as president of the union as part of
James P. Hoffa pension, health and welfare benefits. "We…have negotiated an agreement that will greatly benefit our members at U.P.S. as well as Teamster members in other industries covered by pension and health and welfare funds." Teamster freight members ratified a new, National Master Freight Agreement (NMFA) in February, 2008. Covering 60,000 workers at YRC Worldwide, Yellow Transportation, Roadway and regional units at USF Holland and New Penn Motor Express. On February 20, 2008, Hoffa became the first major union leader to endorse Senator Barack Obama (D-IL) in his bid for President of the United States. Hoffa campaigned in major states for Obama