Complex sentence: Frank P. Zeidler (September 20 1912--July 7 2006) was an American Socialist and mayor of Milwaukee, Wisconsin, serving three terms from 1948 to 1960: the most recent socialist mayor of any major American city.
Split into simpler sentences: Frank P. Zeidler (September 20 1912--July 7 2006) was an American Socialist and mayor of Milwaukee, Wisconsin, serving three terms from 1948 to 1960. He was the most recent socialist mayor of any major American city.