Five years later, in 1956, Mr. Clark was elected to the first of two Senate terms. There, he gained distinction as an intelligent and forceful civil rights advocate, one of the earliest critics of the Vietnam War and a proponent of congressional reform.
"Joe Clark, Richardson Dilworth and Walter Phillips were the Three Musketeers of the reform movement. They were responsible for the halcyon days of 1952 to 1960, when the quality of municipal government in Philadelphia was so high," said W. Thacher Longstreth, the Republican city councilman and a longtime friend.
Mayor Goode called Mr. Clark "an outstanding mayor of the city at a very crucial time. He was an outstanding U.S. senator and public servant. No public servant has done more for the city than Joe Clark."
Mr. Clark was a Social Register liberal whose political philosophy was a compound of noblesse oblige and New Deal idealism, a combination that inclined him to view his principal duty as that of righting wrongs.
Mr. Clark was at first dismissed as a lightweight by old-line politicians, partly because of his private-school background and partly because of his slight build. But he demonstrated an inner toughness that won their respect, if not their approval.
Mr. Clark's tenacity was never more evident than at his May 7, 1951, confrontation with the barons of Philadelphia's Democratic Party - Albert M. Greenfield, John B. Kelly, Matthew McCloskey, Frank J. Myers and James Finnegan - at the old Ritz-Carlton Hotel.
Their message was blunt. Mr. Clark, though he had earlier been promised support for the mayoral election, should step aside in favor of Richardson Dilworth, his longtime ally in reform politics. Dilworth, they pointed out, was older, more experienced and better known.
Dilworth, they told him, was the man they wanted to run for mayor. Warned earlier of their strategy, Mr. Clark cut them short.
"Before we proceed any further," he began, "I think I ought to tell you that less than an hour ago, I released to the press a statement of my irrevocable decision to run for mayor. I intend to run whether or not I have your backing - even if my only supporters are me and my wife. I think our discussion ought to proceed on that basis."
Clearly outfinessed, the aging party leaders finally gave Mr. Clark their support.
Mr. Clark's wealth and formidable vote-pulling powers enabled him to remain free of all political organizations throughout his career. To the distress of some of his admirers, he was not only independent, but he was intolerant of party leaders and their machinery, treating them with an imperious disdain.
In The Challenge of Urban Reform, a comprehensive history of the Clark mayoral years, Professor Kirk F. Petshek wrote, "Clark's most important shortcoming was his failure to appreciate politicians and his tendency to act as if they were beneath him. Too often he made it clear that he thought ward leaders unimportant."
Mr. Clark's dislike of back-room political bosses was effective in his anti-organization campaigning in the city, but it rebounded against him in his unsuccessful 1968 re-election campaign for the U.S. Senate. In Western Pennsylvania, many party leaders withheld their support. Montgomery County Republican Richard S. Schweiker, who ran as a liberal, defeated him with ease.
Mr. Clark, the son of Joseph Sill Clark Sr. and Kate Richardson Avery Clark, was born to "the good life." The elder Clark was a wealthy lawyer and a celebrated tennis champion.
"My father had a wonderful life," Mr. Clark once recalled. "He loved to shoot birds and drink port wine, and he was utterly untroubled by social conscience."
Mr. Clark attended the proper schools, Chestnut Hill Academy and the Middlesex School in Massachusetts, where he played football and baseball, and graduated in 1919 as class valedictorian.
He went on to study at Harvard, specializing in government, history and economics. He was a member of the baseball and track teams, made Phi Beta Kappa and graduated magna cum laude in 1923.
Three years later, Mr. Clark graduated from the University of Pennsylvania Law School, where he was editor of the Law Review. After passing the bar exam, in December 1926 Mr. Clark joined his father's law firm.
And in 1926, Mr. Clark made his first political race - as a progressive candidate for Republican committeeman. He lost.
He broke the Clark family's Republican tradition in 1928 by voting for Democratic presidential candidate Alfred E. Smith, and shortly afterward changed his registration to Democratic. He joined Dilworth, another fledgling lawyer and Democratic convert, in organizing the Warriors, a reform Democratic club.
"We couldn't get anything done as Republicans," Mr. Clark explained.
"Dick (Dilworth) and I were anomalies in city politics," Mr. Clark said. ''We both came from well-to-do families and we knew each other as kids. I like to say that we learned the American way of life together on the beaches of Southampton, Long Island, before World War I."
Dilworth managed Mr. Clark's campaign for City Council in 1934. And in 1936, Mr. Clark managed Dilworth's bid for the state Senate. Both races were unsuccessful and both men turned to their legal practices.
At the age of 39, Mr. Clark entered the Army Air Corps as a captain in August 1941. Mr. Clark first served in the Army Air Corps Planning Headquarters in Washington. When America entered the war, he was transferred to the China-Burma-India theater of operations as Gen. George E. Stratemeyer's senior administrative officer.
Of his war service, Mr. Clark often joked, "I fought most of the war on the grass tennis courts of Delhi." But he was awarded the Bronze Star, the Legion of Merit and the Military Order of the British Empire.
Upon his return to Philadelphia, Mr. Clark planned another venture in politics with Dilworth. The two men were convinced that they had to do something about city government, where the description given by Lincoln Steffens in 1904 still held: "Other American cities, no matter how bad their condition may be, point with scorn to Philadelphia as worse - the 'worst governed city in the country.' "
In 1947, Mr. Clark managed Dilworth's campaign for mayor. The Democratic organization, surprisingly, endorsed Dilworth. Though Republican incumbent Bernard Samuel defeated Dilworth by 93,000 votes, the campaign marked the beginning of the end for the GOP.
Dilworth waged a vigorous streetcorner campaign, arguing that corruption governed City Hall and loudly naming names. Enough people listened that a grand jury was convened and scandals were investigated. A group of civic- minded businessmen organized the Greater Philadelphia Movement.
Then, in 1949, Mr. Clark ran for city controller and Dilworth for treasurer. Both were elected by 100,000-vote pluralities.
As controller, Mr. Clark had two years to probe Republican scandals and report his findings to the public. With relish, he exposed bribes, assorted forms of graft and inefficiencies in the Samuel administration. Many were impeached and indicted. Nine committed suicide.
When he became a mayoral candidate in 1951, Mr. Clark began his campaign on what his investigation had revealed. Using a broom as his symbol, Mr. Clark pledged to sweep out corruption.
His Republican opponent was the Rev. Daniel A. Poling, a well-known Protestant clergyman, who party leaders hoped would dilute the corruption issue.
But Mr. Clark was elected by 124,700 votes as the Democrats also swept 15 to 17 seats on the new City Council. The new charter eliminated the legislature's control over city government and gave the mayor significant administrative, legislative and investigative powers.
Mr. Clark's election gave Philadelphians a sense of belief in their government that they had not held in years. He replaced the city's spoils system with a Civil Service system. He hired lawyers, business executives and academicians for the top positions.
Mr. Clark said that a mayor can attract such talent "only if he holds a high conception of the purpose of political leadership. . . . A good political leader must have the ability to look ahead for the best way to the ideal future of his city and try to lead his community a short distance in the right direction."
Mr. Clark said, years later, that his major achievements as mayor were ''the reform of the police - taking them out of politics" and "the opening of a career service in city government to blacks."
Mr. Clark's strict enforcement of Civil Service regulations, which made it possible for thousands of black people to find jobs for the first time in city government, won him strong support in the black community.
So did his willingness to challenge racist traditions. He took several black friends to lunch at the Philadelphia Cricket Club near his home in Chestnut Hill - the first time in the club's 100-year history that blacks had been guests there.
"If I hadn't been made a life member by my father the day I was born, they probably would have asked for my resignation," Mr. Clark observed.
Mr. Clark pushed through a $20 million tax increase and put the city on a pay-as-you-go fiscal system. This enabled him to increase and improve many city services neglected by previous administrations.
City planners from New York, Chicago, Detroit, New Haven and Newark studied the Clark administration to see if its successful programs could be transplanted in other cities.
Although Mr. Clark was a masterful administrator, one who knew how to use all the proper channels, some of his top staff members found him difficult to work for.
"He was a hard taskmaster," a former aide said. "He was abrupt and aggressive, if opposed. Those reporting to him or suggesting new ideas had better know the answers if they wanted to keep his respect."
His impatience sometimes caused him problems even among his admirers.
Dilworth, an ex-Marine with an explosive temper, sometimes found Mr. Clark ''difficult," and the men came close to a public break in 1955 over who would run for mayor.
While Mr. Clark, in his first news conference as mayor, had said he would run for the Senate in 1956 rather than seek re-election, he later changed his mind. And he didn't tell Dilworth.
Dilworth learned of Mr. Clark's intention to run again when the mayor announced he would run for a second term because, he said, Democratic Chairman William J. Green was trying to "gut the City Charter."
Dilworth felt betrayed by the announcement. He reminded the mayor that Mr. Clark had promised to support him for mayor.
Using much the same tactic as Mr. Clark in 1951, Dilworth resolved the problem head-on. Tired of waiting for a decision, Dilworth said he simply ''announced my candidacy and he supported me." Dilworth was elected mayor in a landslide.
As Mr. Clark's term ended, he began maneuvering for the Senate race. He won the Democratic nomination over the opposition of Philadelphia's Democratic organization.
Mr. Clark was taking on Sen. James H. Duff, a former Republican governor and one of the state's most successful politicians. Duff was a close friend of President Dwight D. Eisenhower and expected to benefit heavily from his coattails.
Mr. Clark defeated Duff by a razor-thin margin - 17,000 votes - but he ran 600,000 votes ahead of the national ticket, and some columnists began to promote Mr. Clark as a potential Democratic presidential candidate in 1960.
A Clark-for-President drive never really got under way, and Mr. Clark later said that he understood why himself. "I could not stand up under the pressures of the presidency. The Senate was my true ambition."
Shortly after his election to the Senate, Mr. Clark asked Sen. Hubert H. Humphrey of Minnesota how to succeed in Washington. "Don't let your ideology embitter your personal relationships," Humphrey counseled. "It won't, if you behave with maturity."
But Mr. Clark soon clashed with Senate Majority Leader Lyndon B. Johnson. He was offended by Johnson's habit of pawing at the man he was talking to, by his salty language and by his hard-sell tactics.
And, more important, he believed Johnson was not pushing for much of the social legislation written into the national Democratic platform - housing, federal aid to education and civil rights.
Mr. Clark prepared a detailed policy statement, based on the 1956 Democratic platform, and asked Johnson to consider its adoption as Senate Democratic policy. Johnson ignored him.
Mr. Clark antagonized John F. Kennedy during the 1960 presidential campaign when he charged that Kennedy was neglecting his Senate responsibilities.
"I think the Senate will pass a minimum wage increase if we can just get Sonny Boy (Kennedy) back from the cricks and hollers long enough to report it out of his committee," Mr. Clark said on the eve of the West Virginia primary. The remark was widely quoted in Republican campaign literature.
He further alienated Kennedy by threatening to support Adlai E. Stevenson during the hotly contested national convention that year.
But once Kennedy was nominated, Mr. Clark campaigned hard for him. His work for Kennedy did not go unnoticed. He was sounded out for a cabinet position, but indicated a preference to remain in the Senate. Kennedy later asked Mr. Clark to draw up a civil rights program for his "New Frontier."
Mr. Clark enjoyed new status in the Senate with a liberal Democratic president and a new majority leader. He wrote and sponsored such major pieces of legislation as the Manpower Development and Training Act and the Area Redevelopment Act.
Kennedy repaid Mr. Clark by making several campaign appearances for him in 1962. Mr. Clark was re-elected by 104,000 votes over Republican James Van Zandt.
Once re-elected, Mr. Clark was appointed to the Democratic steering committee, which determined all committee assignments. But Southern conservatives continued to dominate. Mr. Clark's proposals to involve more liberals in the committee were repeatedly voted down.
Frustrated by his inability to change the Senate and impatient with committee procedures, Mr. Clark took his fight to the Senate floor. In February 1963, he gave a series of speeches, later published in book form as The Senate Establishment.
He asserted, "The Senate Establishment is almost the antithesis of democracy. . . . It is what might be called a self-perpetuating oligarchy, with only mild overtones of a plutocracy."
James MacGregor Burns, the Pulitzer Prize-winning historian from Williams
College, called Mr. Clark's speech ". . . of historical significance because it aims squarely at this century-old coalition as it operates quietly in the Senate. He has moved the power process out of dim and musty committee and caucus rooms into the spotlight of the Senate floor."
Mr. Clark continued his one-man assault on congressional leadership in spite of the obvious penalties.
Mr. Clark's influence at the White House declined after the Kennedy assassination. His relations with Johnson, his old adversary, fluctuated from cool to hostile.
In 1964, Mr. Clark voted for Johnson's Gulf of Tonkin resolution - along with such future Vietnam War critics as J. William Fulbright, Eugene McCarthy and George McGovern. But within a year, Mr. Clark broke with the Johnson administration's war policy.
In the meantime, Mr. Clark faced political problems back home, largely of his own making.
During the 1963 primary elections, Mr. Clark had vigorously supported challenges to the Democratic Party organizations in far reaches of the state, asserting, "It's time to knock sleazy government out of the box in Western Pennsylvania."
It was not a winning campaign. Most of the Clark-supported candidates were beaten, and party stalwarts vowed to help defeat him in 1968.
They were helped by the National Rifle Association, which had singled Mr. Clark out as a major target since he endorsed strong gun registration laws. In rural Pennsylvania, literature was distributed to hunters and farmers solemnly warning that, "Clark Wants to Take Away Your Guns."
For the first time, he found himself opposed by a younger man, one who seemed equally progressive. In a series of televised debates, Richard S. Schweiker held his own against the aging reformer.
Unable to overcome the opposition of Western Pennsylvania Democratic leaders and the gun enthusiasts, Mr. Clark lost to Schweiker by 280,000 votes.
Mr. Clark took the loss gracefully, although he admitted later that he was ''quite flabbergasted with the results."
Longstreth said he believes Mr. Clark was "very hurt" by the defeat.
After his defeat, he spent two years as president of World Federalists U.S.A., a Washington-based group seeking to foster interest in development of world government. He also was chairman of the Coalition on National Priorities and Military Policy. And he continued to attend Capitol Hill luncheon meetings of Members of Congress for Peace Through Law, a group he organized.
He lectured at the University of Minnesota, Michigan State University, Temple University, Haverford College, Chestnut Hill College and the University of Pennsylvania.
Even in retirement, Mr. Clark continued to support quixotic causes. He returned to Philadelphia politics during the 1971 mayoral campaign, determined to prevent the election of Frank L. Rizzo. Mr. Clark actively supported William J. Green Jr.'s losing effort in the Democratic primary, and, in the fall, supported Republican Longstreth.
In 1975, when Rizzo won the Democratic nomination, Mr. Clark became chairman of Charles Bowser's independent campaign. "I, for one, am not prepared to live in a fascist city," he said.
Mr. Clark's financial as well as political fortunes declined in recent years. His 1967 divorce from Noel Hall Clark, his wife of 31 years, drained much of his wealth. Before the divorce, Mr. Clark had listed his net worth at more than $1.1 million.
His wife, wealthy in her own right, received a large settlement. In 1968, Mr. Clark placed his net worth at $523,454. Five years later, his assets had dwindled to "around $250,000."
Mr. Clark married public relations executive Iris Cole Richey, 20 years his junior, shortly after the divorce. She shared his interests in politics and the outdoors. The Clarks often played mixed-doubles tennis and occasionally
went horseback riding together.
And in odd moments, Mr. Clark tried his hand at writing again, but without marked success. He expressed disappointment at publishers' rejection slips for an autobiography, which he planned to call The Six Lives of Joseph Sill Clark.
No one familiar with Mr. Clark's political life could doubt that he had an ego. Associates suggested that his civility was maintained out of an inbred sense of noblesse oblige and the social expectation that anyone with his background would quite naturally be a "gentleman."
Those who dealt with him on a daily basis often found him cold, severe, somewhere imperious. Critics called him a snob. But free of pressures of the day, secure in his home, he became a different man.
Reporters who covered his administration and knew him during his years in Washington often expressed shock to find that at night he exuded a friendly warmth, offered a boyish charm and exhibited a degree of understanding that countered his persona of the day.
In recent years, Mr. Clark had not been well. "He had many physical problems as a result of age, and he had his good days and his bad days," said Gregory Harvey, a lawyer involved in politics and a longtime friend.
Mr. Clark is survived by his wife, Iris; a son, Joseph S. Jr.; a daughter, Noel Miller; a stepdaughter, seven grandchildren and three great- grandchildren.
A private funeral was held for family members yesterday afternoon. A memorial service will be held at 11:30 a.m. Saturday at the Unitarian Church of Germantown, 6511 Lincoln Drive.