From 1910-1960 (with a few short breaks) Milwaukee was governed by a historic trio of socialist mayors: Emil Seidel, Daniel Hoan, and Frank Zeidler. These “sewer socialist” mayors, along with the many socialist aldermen and other city and county officials with whom they served, shaped the city we now know through their energetic efforts, including developing the shoreline, city boundaries, parks and riverfronts, public health infrastructure, even the city’s annual Christmas tree tradition. The UWM Archives are home to the personal and mayoral papers of the first of those mayors, Emil Seidel. We have digitized and made available the entirety of Seidel’s mayoral and personal papers including unpublished autobiography. Seidel served as mayor from 1910-1912. His papers provide a first-hand view of the issues and concerns that drove his tenure as mayor, and into the early history of socialism in Milwaukee.