With the rapid growth of industrial workers in the auto factories, labor unions such as the American Federation of Labor and the United Auto Workers fought to organize workers to gain them better working conditions and wages. They initiated strikes and other tactics in support of improvements such as the 8-hour day/40-hour work week, increased wages, greater benefits and improved working conditions. The labor activism during those years increased influence of union leaders in the city such as Jimmy Hoffa of the Teamsters and Walter Reuther of the Autoworkers.