He worked for Western Electric, and in the 1930s became a leader of its employee organization, in 1943 becoming president of the National Federation of Telephone Workers.
[1][2] This experience led the union to reform as the Communication Workers of America (CWA), with Beirne continuing as president.
It affiliated with the Congress of Industrial Organizations (CIO), of which Beirne became a vice president, leading opposition to communist-led unions in the federation.
[1][2] Under Beirne's leadership, the CWA supported unionism in Latin America, founding the American Institute for Free Labor Development.
Unlike the majority of the AFL-CIO leadership, he supported George McGovern in the 1972 United States presidential election, and served as secretary-treasurer of a national labor committee backing him.