Joseph S . Clark , Jr . Joseph Sill Clark , Jr . ( October 21 , 1901January 12 , 1990 ) was an American lawyer and politician . A member of the Democratic Party , he served as a United States Senator from Pennsylvania from 1957 to 1969 . He previously served as the 90th Mayor of Philadelphia from 1952 to 1956 . Clark was the only Unitarian Universalist elected to a major office in Pennsylvania in the modern era . Early life and education . One of two children , Joseph Clark was born in Philadelphia , Pennsylvania , to Joseph Sill Clark , Sr . and Kate Richardson Avery . His father , a longtime lawyer in Germantown , 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 , who invented Tabasco sauce . He 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 prizes , including the John Harvard scholarship for high academic distinction . He was elected to Phi Beta Kappa and graduated " magna cum laude " in 1923 with a Bachelor of Science degree in government , history and economics . Clark , who had spent time at the Bar B C Dude Ranch in Jackson Hole , became a partner in the Double Diamond Dude Ranch in 1924 . He later returned to Philadelphia and enrolled at the University of Pennsylvania Law School , where he was a member of St . Anthony Hall and editor of the " Law Review " . He earned his Bachelor of Laws degree in 1926 . Early career . In December 1926 , Clark was admitted to the bar and became an associate with his father ' s law firm of Clark , Clark , McCarthy and Wagner . That same year , he made his first entry into politics when he unsuccessfully ran as a progressive candidate for Republican committeeman . In 1928 , he left the Republican Party and became a Democrat , supporting Al Smith in that year ' s presidential election . During the 1928 election , Clark founded the Democratic Warriors Club with Richardson Dilworth , beginning a long political partnership between the two . Both men became active in the reform movement to end corruption in city government , which was long controlled by a Republican machine . Clark was an unsuccessful candidate for the Philadelphia City Council in 1933 , with Dilworth serving as his campaign manager . The following year , he joined the firm of Dechert , Bok , Smith and Clark , and continued to practice law for seven years . He managed Dilworth ' s unsuccessful campaign for the Pennsylvania State Senate in 1934 . From 1934 to 1935 , he served as Deputy Attorney General of Pennsylvania . In this capacity , he engaged in trial work related to the closing of banks . In August 1941 , Clark enlisted in the United States Army Air Forces ( AAF ) and was assigned as a captain in the Officers ' Reserve Corps Headquarters at Washington , D . C . He later became director of the Organizational Planning Headquarters with the AAF . Following the entry of the United States into World War II , he was transferred to the China Burma India Theater as deputy chief of staff to General George E . Stratemeyer . He briefly served as acting chief of staff to General Stratemeyer , and attained the rank of colonel on October 15 , 1943 . He was awarded the Bronze Star Medal , Legion of Merit , and Military Order of the British Empire . Returning to the United States in September 1945 , he accompanied General Stratemeyer to Washington , D . C . , where he helped design plans to defend the nation against air raids . Following his return to Philadelphia , Clark resumed his political activity and his partnership with Dilworth . He was manager of Dilworth ' s unsuccessful campaign for Mayor of Philadelphia against Republican incumbent Bernard Samuel in 1947 . He then served as chairman of the citizens ' committee for President Harry S . Truman in the 1948 election , and as chairman of the Philadelphia chapter of the Americans for Democratic Action from 1948 to 1949 . Running as a reform Democrat , Clark was elected city controller in 1949 , winning by more than 100 , 000 votes . Meanwhile , Dilworth was elected city treasurer by a similar margin . Serving from 1950 to 1952 , Clark investigated and publicized scandals within the Republican - controlled city government , including the embezzlement of tax money and court funds , imprisonment of the fire marshal , falsification of records , and corruption in the water bureau . Many officials were impeached or indicted as a result , and nine even committed suicide . Mayor of Philadelphia . Clark announced his candidacy for Mayor of Philadelphia in May 1951 . Democratic leaders had wanted Dilworth to run for mayor , but Clark released a press statement declaring his " irrevocable decision to run for mayor . " Dilworth instead successfully ran for District Attorney of Philadelphia . Running on his record as city controller , Clark often used a broom while campaigning as a symbol of his pledge to " sweep out " corruption . His Republican challenger was Daniel A . Poling , a Baptist clergyman and editor of the " Christian Herald " . Clark was endorsed by several labor unions , Americans for Democratic Action , and the " Philadelphia Inquirer " . On November 6 , 1951 , he defeated Poling by a margin of 124 , 700 votes . With his victory , Clark became the first Democrat to be elected Mayor of Philadelphia since 1884 . Clark was inaugurated as the 90th Mayor of Philadelphia on January 7 , 1952 . He was the first mayor to serve under Philadelphia ' s Home Rule Charter , which had reorganized city government by merging Philadelphia ' s city and county offices , establishing a limit of two successive terms for mayor , replacing patronage with a merit system for civil servants , and giving the mayor increased administrative , legislative , and investigative powers . During his administration , he reduced corruption within the Police Department and appointed several African Americans to city jobs . He adopted a $ 20 million tax increase and established a pay - as - you - go system . He created low - income housing projects , also establishing the position of housing coordinator . He also refused to accept personal gifts . His tenure also saw the transformation of the Penn Center and the Philadelphia waterfront . In 1952 , Clark launched a television series " Tell It To the Mayor " in which he and other city officials answered questions about his administration . He endorsed Senator Estes Kefauver for the Democratic nomination in the 1952 presidential election . In 1955 , he chartered the Food Distribution Center Corporation to create a new food market , and established the Urban Traffic and Transportation Board to design a mass transit system . U . S . Senate . Clark , who had promised to serve as mayor for only one term , announced his candidacy for the United States Senate in 1956 . After winning the Democratic nomination over the opposition of Philadelphia ' s party leaders , he faced first - term Republican incumbent James H . Duff , a popular former governor , in the general election . During the campaign , Clark ran on a liberal platform which included support for increasing the minimum wage , expanding Social Security , and repealing the Taft – Hartley Act . He also criticized President Dwight D . Eisenhower on international and domestic matters , and attacked Senator Duff ' s poor attendance record . On November 6 , 1956 , Clark narrowly defeated Duff by a margin of 50 . 1 % - 49 . 7 % , winning by less than 18 , 000 out of 4 . 5 million votes cast . At the same time in the presidential election , President Eisenhower carried Pennsylvania by well over 600 , 000 votes . During his early tenure in the Senate , Clark earned a reputation as a strong supporter of civil rights and congressional reform . He sponsored the Manpower Development and Training Act and the Area Redevelopment Act . He often clashed with Lyndon B . Johnson while the latter was Senate Majority Leader . In 1962 , Clark was re - elected to a second term after narrowly defeating Congressman James E . Van Zandt by a 51 % - 49 % margin . Clark was appointed to the Democratic Steering Committee in 1963 , but conservative Southern Democrats thwarted his efforts to appoint more liberal Senators to committees . He was a critic of the Senate itself , which he called a " self - perpetuating oligarchy " in a 1963 address on the Senate floor . He challenged the seniority system and the filibuster . In 1964 , he endorsed Genevieve Blatt , the state Secretary of Internal Affairs , over Judge Michael Musmanno in the Democratic senatorial primary . Clark ' s opposition to Musmanno was not well received by the Italian American community , who largely voted against Clark in 1968 . A member of the Senate Foreign Relations Committee , he voted for the Gulf of Tonkin Resolution in 1964 but soon became an outspoken opponent of the Vietnam War , condemning the war ' s escalation in 1965 . In 1968 , Clark was defeated for re - election to a third term by Congressman Richard Schweiker , losing by a margin of 52 % - 46 % . His defeat is generally credited to his support of gun control and opposition to the Vietnam War . His campaign chairman in 1968 was Bucks County author James A . Michener . Later life and death . Following his departure from the Senate , Clark served as a professor at Temple University in 1969 . He was president of World Federalists U . S . A . , an organization promoting the creation of a world government , from 1969 to 1971 . He also served as chairman of the Coalition on National Priorities and Military Policy , and continued to attend meetings of Members of Congress for Peace Through Law . A strong opponent of Mayor Frank Rizzo , he supported William J . Green , III in the 1971 Democratic primary and then Republican W . Thacher Longstreth in the general election . He was chairman of independent candidate Charles Bowser ' s campaign in 1975 . Clark died at his home in Chestnut Hill , at age 88 . His remains were cremated . Personal life and family . Joseph Clark was descended from a prominent financial family in Philadelphia . His great - grandfather , Enoch White Clark , was the founder of E . W . Clark & Co . Enoch ' s son Edward was Clark ' s paternal grandfather and brother of Clarence Howard Clark , Sr . Clarence , Sr . ' s son Clarence , Jr . served as president of the Centennial National Bank . Clark was the nephew of Edward Walter Clark , Jr . , commodore of the Philadelphia Corinthian Yacht Club and father of Edward III ; Clarence Munroe Clark , a noted tennis player like his brother ; and Percy Clark , a lawyer and noted cricketer . Percy ' s daughter Mary was married to Nelson Rockefeller from 1930 to 1962 , before he served as Vice President of the United States . Clark ' s paternal grandmother was the daughter of Joseph and Jane ( née Todhunter ) Sill , who were social reformers and leaders in antebellum Philadelphia ' s benevolence movement . Joseph Sill served as secretary , vice president , and president of the St . George Society of Philadelphia , an aid organization for English immigrants . Clark was married three times and had two children . He and his first wife had one son , Joseph S . Clark III . He was married to his second wife , Noel Hall , from April 1935 until their divorce in September 1967 . He and Noel had one daughter , Noel Clairborne Clark . Two weeks after his divorce , Clark married Iris Cole Richey , a former editor of the " Pennsylvania Manual " , to whom he remained married until his death .