I know all about this song. It comes from the movie "The Inheritance". My father became a Vice President of the Union when it was merged with the Textile Workers and became the Amalgamated Clothing and Textile Workers Union or ACTWU.   The film was to commemorate the 50th anniversary of the labor union and it is well worth the view. The best source of information regarding this unions and others is at the Cornell University Library in Ithaca NY.