The United Hatters, Cap and Millinery Workers International Union, also known by acronyms including UHCMW, U.H.C. & M.W.I.U. and UHC & MWIU, was a 20th-century American labor union. In 1934, the United Hatters of North America (UHNA), that was formed in 1896, and the Cloth Hat, Cap and Millinery Workers International Union (CHCMW), that was formed in 1901, both based in New York, ended their competition by merging to form the United Hatters, Cap and Millinery Workers International Union (UHCMW). As the hat and millinery trade went into decline in the US, in 1983 UHCMW merged into the Amalgamated Clothing and Textile Workers Union (ACTWU).