Joseph Sill Clark Jr. (October 21, 1901January 12, 1990) was an American writer, lawyer and politician. A member of the Democratic Party, he served as the 90th Mayor of Philadelphia from 1952 to 1956 and as a United States Senator from Pennsylvania from 1957 to 1969. Clark was the only Unitarian Universalist elected to a major office in Pennsylvania in the modern era. The son of attorney and tennis player Joseph Sill Clark Sr., Clark pursued a legal career in Philadelphia after graduating from the University of Pennsylvania Law School. He became involved in a reform movement that sought to break the power of the city's Republican political machine. After serving in the United States Army Air Forces during World War II, Clark won election as city controller in 1949. In this capacity, he investigated and publicized scandals in the city government. In 1951, Clark won election as Mayor of Philadelphia, becoming the first Democrat to do so since 1884. As mayor, he sought to reduce corruption in city government and created low-income housing projects. After one term as mayor, Clark narrowly defeated incumbent Republican Senator James H. Duff in the 1956 Senate election. Clark earned a reputation as a strong supporter of civil rights and worked to appoint liberal committee members from his perch on the Democratic Steering Committee. Clark narrowly won re-election in 1962 but was defeated in 1968 by Congressman Richard Schweiker. His defeat is generally credited to his support of gun control and opposition to the Vietnam War. After leaving office, Clark became a professor at Temple University. Early life and education One of two children, Joseph Clark was born in Philadelphia to Joseph Sill Clark Sr. and Kate Richardson Avery. His father, a longtime lawyer in the Germantown section of the city, was also a national tennis champion who won the 1885 U.S. National Championship in doubles with Dick Sears. His mother, whose family owned Avery Island in Louisiana, was the niece of Edmund McIlhenny, the inventor of Tabasco sauce. Clark was raised in the Chestnut Hill section of Philadelphia, and received his early education at Chestnut Hill Academy. He then attended Middlesex School in Concord, Massachusetts, where he played on the school's baseball and football teams. He graduated from Middlesex in 1919 as class valedictorian. Clark studied at Harvard University, where he was a member of the baseball and track teams. He won several