The first labor union in the United States formed in 1794. Since then, union membership has grown considerably from the small group of shoemakers in Philadelphia, Pennsylvania who were the first to organize. Approximately 15.3 million Americans belong to labor unions as of 2009, a figure that equated to roughly 12.3 percent of the work force in the United states, according the U.S. Bureau of Labor Statistics. Like the earliest union, modern labor unions in the United States typically include the members of one or several industries.

United Mine Workers of America

The United Mine Workers of America is a division of the AFL-CIO network of labor unions in the United States. The group began in 1890 in Columbus, Ohio, and had its headquarters in Triangle, Virginia, as of November 2010. Surface and underground coal miners, manufacturers, health care workers and some public service workers such as waste management and law enforcement professionals comprise the membership of the group. The organization publishes a magazine, the "United Mine Workers Journal," for its members. The union also sponsors the Lorin E. Kerr Scholarships, which provide money to fund college educations for union members or their dependents. Through its nationwide Career Centers, the United Mine Workers of America helps members locate employment and offers safety training programs for miners.

United Auto Workers

The United Auto Workers labor union became officially chartered by the AFL in 1935 to represent the interests of workers in auto assembly and manufacturing plants. The group has its headquarters in Detroit, Michigan, the primary center for the automobile industry in the United States. As of 2009, the group had more than 390,000 active members and more than 600,000 retired members, bringing its total membership to more than 1 million people, explains the group's website. Members belong to more than 750 regional chapters throughout the United States. For its members, the union had the responsibility for negotiating 2,500 different contracts as of November 2010. The United Auto Workers' "Solidarity" magazine is released six times per year.

National Education Association

The National Education Association has represented educators at public schools in the United States since 1857. Headquartered in Washington, D.C., the union boasted more than 3.2 million members nationwide as of November 2010, according to its website. In addition to public school teachers, administrators, substitute teachers and post-secondary school instructors also make up the membership. The National Education Association offers professional development workshops and seminars as well as lesson plan ideas for its members. Through its NEA Foundation, the union offers grants to fund school programs and grants awards to accomplished educators in the field. The union also publishes books and online articles for teachers on instructional methods and classroom ideas.

International Brotherhood of Teamsters

The International Brotherhood of Teamsters formed in 1901 and operates from headquarters in Washington, D.C. The labor union primarily represents the interests of truck drivers, but also counts locomotive engineers and graphics communications professionals among its members. The group had 1.4 million members as of November 2010 and provided services for around 500,000 retirees. The membership meets through 1,900 affiliates across the United States and Canada. The International Brotherhood of Teamsters offers members employment assistance through online job postings. Through its local affiliates, the union offers training courses in safety and other topics of interest. The organization publishes "Teamster" magazine six times per year.