On November 9, 1935, the Committee for Industrial Organizations was founded by John L. Lewis of the United Mine Workers of America and the leaders of seven other unions who opposed the American Federation of Labor’s refusal to organize industrial workers. Lewis became the CIO’s first president and maintained that position until 1940.
The CIO was founded just one month after the American Federation of Labor’s annual convention held in Atlantic City, New Jersey. There, the AFL rejected the call for industrial unionism, the organization of all workers in a given industry under one union, in favor of craft unionism, in which workers are organized according to specific trades within an industry. The AFL also rejected the formation of a labor party and voted to prevent members suspected of being communists from assuming leadership positions within the organization.
The CIO was initially formed as an opposition movement within the AFL, releasing a statement upon its founding saying it would continue to fight for industrial unionism within the federation. “It is the purpose of the committee,” the statement read, “to encourage and promote organization of the workers in the mass production and unorganized industries of the nation and affiliation with the American Federation of Labor. Its functions will be educational and advisory and the committee and its representatives will cooperate for the recognition and acceptance of modern collective bargaining in such industries.”
The members of the CIO were expelled from the AFL within a year, after which they would rename themselves the Congress of Industrial Organizations. As an independent organization, the CIO experienced an explosive growth in membership. By 1937, it had organized roughly 4 million workers under its banner.
http://www.wsws.org/articles/2010/nov2010/twih-n08.shtml#75