McCarthy was elected an international vice president of the Teamsters in 1969. He was elected president of Joint Council 10, which oversaw all Teamsters locals in New England, in 1972. McCarthy ran for election for First Vice President, then the union's number-two position, in 1984.
McCarthy rose through the ranks of the Teamsters in 1969, becoming an international vice president. He then became president of Joint Council 10, which managed all New England locals, in 1972. In 1984, McCarthy ran for election to the union's second-most important position: First Vice President.