[4] Later, however, he credited his adoption of socialism to reading left-wing literature, with the majority being written by Eugene V. Debs and Norman Thomas during the Great Depression.

Carl was killed at sea when his ship was lost and became a local hero, helping to pave the way for his younger brother to become mayor.

In 1948 Frank Zeidler ran for mayor in a crowded field of fourteen candidates and won, undoubtedly aided by the familiarity of his surname.

Zeidler was Milwaukee's third Socialist mayor (after Emil Seidel [1910-12] and Daniel Hoan [1916-40]), making Milwaukee the largest American city to elect three Socialists to its highest office (a fact that singer Alice Cooper pointed out in the 1992 film Wayne's World).

Suburban residents and governments fiercely resisted annexation and the politics of regional Milwaukee became highly factional.

[8] A 1993 survey of historians, political scientists and urban experts conducted by Melvin G. Holli of the University of Illinois at Chicago ranked Zeidler as the twenty-first-best American big-city mayor to have served between the years 1820 and 1993.

[10] After leaving office, Frank Zeidler worked as a mediator, as development director for Alverno College, and served in the administration of Wisconsin Governor John W. Reynolds.

As a leader of the Public Enterprise Committee, Zeidler was a frequent and severe critic of his successor, Henry Maier.

He and his running mate, J. Quinn Brisben, received 6,038 votes, including approximately 2,500 in Milwaukee County, Wisconsin.

[14] Zeidler wrote several books, including not only treatises on municipal government, labor law, socialism, and Milwaukee history, but poetry, renditions of four of Shakespeare's plays into present-day English, and children's stories.

[18] The Milwaukee Public Library's historic collections are housed in the Frank P. Zeidler Humanities Room, named in his honor.

[citation needed] On May 21, 2006, he received an honorary Doctor of Humane Letters degree from Cardinal Stritch University in Milwaukee.

Zeidler Union Park (originally named for priest and explorer Jacques Marquette)[19] now hosts the Westown Farmer's Market and other smaller festivals and gatherings.