Trade union in the US and Canada
The Operative Plasterers' and Cement Masons' International Association of the United States and Canada (OPCMIA) is a trade union of plasterers and cement masons in the construction industry in the United States and Canada. Members of the union finish interior walls and ceilings of buildings and apply plaster on masonry, metal, and wire lath or gypsum. Cement masons are responsible for all concrete construction, including pouring and finishing of slabs, steps, wall tops, curbs and gutters, sidewalks, and paving. The organization is a member union of the AFL–CIO and Canadian Labour Congress.
History.
The union traces its roots to the era of the American Civil War, when an organization known variously as the National Plasterer's Union or the National Plasterers Organization attempted to unify the various local craft unions that represented workers in the trade.
The modern organization was formed in 1882, when a number of locals who had supported the Cincinnati, Ohio local in a strike earlier that year met in St. Louis, Missouri, to reestablish a national organization.
In 1946 the union established a program, in conjunction with the Contracting Plasterers' International Association and the Associated General Contractors, to establish national apprentice training standards. The union trained a large number of veterans of World War II in its apprenticeship programs, while curtailing the competition from non-union contractors. 
In 1960 the union followed many other U.S. unions in moving its headquarters, transferring them from Cleveland to the Washington, D.C. region. It is currently headquartered at Columbia, Maryland.
1882: Michael Mulvihill
1883: James W. Smith
1908: John H. Donlin
1912: Edward J. McGivern
1927: Michael J. Colleran
1940: John E. Rooney
1959: Edward J. Leonard
1970: Joseph P. Power
1981: Melvin H. Roots
Robert J. Holton
1996: John J. Dougherty
2007: Patrick Finley
2016: Daniel Stepano
References.
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