Reuben George Soderstrom was an American leader of organized labor who served as President of the Illinois State Federation of Labor (ISFL) and Illinois AFL-CIO from 1930 to 1970. A key figure in Chicago and Illinois politics, he also played a pivotal role in American labor history by helping to define national labor policy after the formation of the AFL–CIO in 1955. Soderstrom advised and was courted by multiple U.S. presidents seeking his endorsement and the votes of the over 1.3 million laborers he represented. The longest-serving state federation chief in American labor history, he passed seminal labor legislation and increased his organization's membership five-fold, transforming it into one of the most powerful labor bodies in the United States.

Labor unions represent United States workers in many industries recognized under US labor law since the 1935 enactment of the National Labor Relations Act. Their activity today centers on collective bargaining over wages, benefits, and working conditions for their membership, and on representing their members in disputes with management over violations of contract provisions. Larger labor unions also typically engage in lobbying activities and electioneering at the state and federal level.