This publication attempts to explain, through historical description, the organizational structure of labor unions in the U.S. and the influence of major unions over the initiation of decision making policies governing their membership. Begun in 1792, with the unification of a group of Philadelphia shoemakers, labor unions spread from local to national by 1860. Competition of products side by side in the same market or town as well as that experienced from immigrants entering the country in increasing numbers, soon led to the development of the American Federation of Labor (AFL), an organization which brought together national trade unions. The enactment of federal legislation in 1930 which protected the worker caused a tremendous increase in union membership. In 1938 the Committee for Industrial Organization (CIO), which was later changed to the Congress of Industrial Organizations was established as a result of confusion and differences of opinion within the AFL. A merger between the two groups produced the currently existing AFL-CIO from which state and city-wide organizations have emerged, each having a certain interdependence, yet maintaining a great degree of autonomy. (SN)