[fortheDeclaration]

1949 - Communism polarized the labor movement. Walter Reuther began to purge leftists from the UAW. The CIO expelled 9 communist-led unions.

http://history.sandiego.edu/gen/soc/labor.html

[BlackElk]

Walter and Victor Reuther led the UAW but also had volunteered to work in soviet auto plants in the 1930s. They signed off on their letters home: "Yours for a soviet America, Walter and Vic Reuther." The UAW itself was expelled from the AFL-CIO when Walter Reuther was running the union.

That is a curious chronology of labor that you linked. It seems to ignore that little matter of the merger between the AFL and the CIO. Not that the paleos make distinctions in labor history that would notice little things like that.