In 1890 Local #32 in Duluth became the first Sheet Metal Workers’ local union in Minnesota, joined a few short years later by Locals #9 in St. Paul (1892) and #40 in Minneapolis (1893). By the early 1900’s the SMWIA had spread throughout the state with additional locals from Winona in the southeast to Bemidji in the northwest.

In 1918 the two locals in the Twin Cities merged to form Local #34, only to split 13 years later becoming Locals #34 (Minneapolis) and #76 (St. Paul). From the 1930’s through the 1960’s locals were formed throughout Minnesota and the Dakotas until there was close to 20 separate locals in the three states.

Economic conditions and common sense ushered in a period of consolidation over the next 20 years. Individual locals in northern and southern Minnesota and throughout the Dakotas merged together for strength. By the late 1970’s, one local, #14, serviced both the Dakotas. Local #32, Duluth, covered the Northern third of Minnesota, while Local #218, Rochester, covered the southern third of Minnesota. This period of mergers continued until by 1983 only two building trades locals remained in Minnesota. Local #76 in St. Paul, taking in most of the northern and southern parts of the state, and Local #34 in Minneapolis that covered the broad midsection of Minnesota from Brainerd to the Minnesota River.

In June of 1983, the SMWIA amalgamated the two nearly equal locals to form Local #10.  1985 saw the remerging of Production Worker’s Local #547 into Local #10. Originally part of Local #34, the production local had been independent since 1957. The final piece that makes up Local #10 came into place in 1991 with the merger of Local #14, which covered North and South Dakota.