In 1935, led by John L. Lewis of the United Mine Workers of America, a group of union members split from the large American Federation of Labor (AFL). Calling itself the Congress of Industrial Organizations (CIO), the group launched a bitter struggle with the AFL that occasionally erupted in violence. In 1955, the CIO rejoined the AFL, forming the American Federation of Labor-Congress of Industrial Organizations (AFL-CIO).
AFL and CIO Rivals
May 14, 2012