The United Paper Workers International Union (UPIU) represents over 250,000 men and women in the wood products industry in the United States and Canada. Prior to 1937, the International Brotherhood of Papermakers and the International Brotherhood of Pulp, Sulphite, and Paper Mill Workers represented labor in the paper industry. In 1937, the Congress of Industrial Organizations established United Paper Workers of America. The union of the American Federation of Labor and the CIO in 1957 resulted in the formation of the United Pulp and Paper workers (UPP). In 1972, the UPP merged with sulphite workers to form the UPIU.
UPIU locals 21, 110 and 209 are located in Escanaba, Michigan, at the Mead, Inc., paper plant.