The Bureau of Labor Statistics released a report recently on labor stats by state and nationwide in the US. California had the most union members of any state in the United States, with 2.5 million unionized workers, but New York State came in second, with 2 million. North Carolina has the least membership, only about 3/1%. Across the nation, union membership remains generally higher among men than women by about 2%. The highest union membership was generally found among government workers, specifically teachers, police officers, and fire-fighters. Among the private sector, highest membership was in telecommunications, transportation, and construction.
See "Union membership stays strong in NYS", Bizjounals.com, January 24, 2010