 He was elected the local's president in 1956, and over the next 27 years expanded the union's membership from 1,000 to 20,000 and branched out to include custodial workers, fire fighters, security guards and non-salaried hospital workers.Cordtz was also elected president of SEIU Joint Council 35 (a coalition of Detroit-area SEIU locals), and president of Service Employees Central States Conference (a coalition of SEIU councils and state, regional and local bodies in the Midwest).Cordtz also served as vice-president of Metropolitan Detroit AFL-CIO and on the board of directors of the Michigan State AFL-CIO.