began to expand dramatically and mature organizationally under Tobin. He pushed for the development of "joint councils" to which all local unions were forced to affiliate. Varying in geographical and industrial jurisdiction, the joint councils became important incubators for up-and-coming leadership and negotiating master agreements which covered all employers in a given industry. Tobin also actively discouraged strikes in order to bring discipline to the union and encourage employers to sign contracts, and founded and edited the union magazine, the International Teamster. Under Tobin, the Teamsters also first developed the "regional conference" system (developed by Dave Beck in Seattle), which provided stability, organizing strength, and leadership to the international union. Tobin undertook long jurisdictional battles with many unions during this period. Fierce disputes occurred between the Teamsters and the Gasoline State Operators' National Council (an AFL federal union of gas station attendants), the International Longshoremen's Association, the Retail Clerks International Union, and the Brotherhood of Railway Clerks. The most significant disagreement, however, was with the United Brewery Workers over the right to represent beer wagon drivers. While the Teamsters lost this battle in 1913, when the AFL awarded jurisdiction to the Brewers, they won when the issue came before the AFL Executive Board again in 1933, when the Brewers were still recovering from their near-elimination during Prohibition. The raids and new member organizing in the 1930s led to significant membership increases. Teamster membership stood at just 82,000 in 1932. Tobin took advantage of the wave of pro-union sentiment engendered by the passage of the National Industrial Recovery Act, and by 1935 union membership had increased nearly 65 percent to 135,000. By 1941, Tobin had a dues-paying membership of 530,000—making the Teamsters the fastest-growing labor union in the United States. One of the most significant events in union history occurred in 1934. A group of radicals in Local 574 in Minneapolis—led by Farrell Dobbs, Carl Skoglund, and the Dunne brothers (Ray, Miles and Grant), all members of the Trotskyist Communist League of America—began successfully organizing coal truck drivers in the winter of 1933. Tobin, an ardent anti-communist, opposed their efforts and refused to support their 1933 strike. Local 574 struck again in 1934, leading to several riots over a nine-day period in May. When the employers' association reneged on the agreement, Local 574 resumed the strike, although it ended again after nine days when martial law was declared by Governor Floyd