1951 Philadelphia municipal election
The 1951 Philadelphia municipal election, held on Tuesday, November 6, was the first election under the city's new charter, which had been approved by the voters in April, and the first Democratic victory in the city in more than a half-century. The positions contested were those of mayor and district attorney, and all seventeen city council seats.
Source: Wikipedia — 1951 Philadelphia municipal election (CC BY-SA 4.0)