IT MAY HAVE been the only time in her 66-year existence that Karen Asper Jordan didn't know what to say.

It happened on the afternoon of Aug. 3, 1965 - 50 years ago. For 13 weeks, the 16-year-old Simon Gratz High School student had thrown her body and soul into the fight to desegregate Girard College in North Philadelphia, a stone's throw from her home.

As a charter member of civil-rights activist Cecil B. Moore's "Young Militants," Karen Asper had sung "freedom songs" into the summer nights and would scream bloody murder that coming winter when she saw cops beat her friend nicknamed "Tree" to within an inch of his life at a protest.

On this hot August day, she joined thousands to watch the Rev. Dr. Martin Luther King Jr., awarded the Nobel Peace Prize just months earlier, take up their cause - standing in front of the massive stone fortress that had been established as a whites-only school for orphans by 19th century industrialist Stephen Girard and declaring it "a kind of a Berlin Wall to keep the colored children of God out."

Caught up in the almost holy fervor of the moment, Jordan and other members of Moore's youthful army raced on foot to King's next stop at 22nd Street and Columbia Avenue, where a destructive three-day riot had erupted just one year earlier. She let a friend know she'd like to meet the man of the hour, and within seconds the teenager was standing on the back of a flatbed truck, face to face with a future American icon.

She stuttered, finally coming out with, "Could I shake your hand?" King laughed and instead gave her a hug. Jordan later would recall that it felt as if she'd met God. "When I walked off that flatbed, I was walking on air," Jordan said. She had played a walk-on role in what was arguably the most pivotal two days in the push for civil rights in Philadelphia during the tumultuous 1960s.

King's two-day stop here during his 1965 "Freedom Now" tour - memorialized with a large mural and historic marker at 40th Street and Lancaster Avenue, where he spoke to a crowd of 10,000 - brought national attention to the fight to integrate the Girard campus, which the activists finally won after months of contentious protest and the lengthy court battle that followed.

But another drama was taking place backstage. King, his allies, and Philadelphia activists including the charismatic and occasionally cranky Moore, were grappling with how to bring the spirit of King's recent victories in the South - in Birmingham and Selma - up North. Could marches and mass protests break down the more-entrenched walls of joblessness, police brutality, and school inequality that existed in Northern cities? And should that movement be nonviolent? Could it be?

Matthew Countryman, a Philly native and University of Michigan history professor who chronicled the civil-rights movement here in his book Up South, said that King's August 1965 visit was something of an audition - that the head of the Southern Christian Leadership Conference (SCLC) was actively looking for a Northern city to mount a new campaign in 1966. And Philadelphia - a city that King knew well from his Chester theological studies and a 1950 incident in which he'd been bounced at gunpoint from a Maple Shade, N.J., bar because he was black - seemed the logical choice.

But one giant obstacle stood between King and a massive Philadelphia campaign: Cecil B. Moore.

In 1965, the head of the Philadelphia NAACP was looking to assert his leadership within the city's black community. Embarrassed by the 1964 riot when young looters ignored his pleas to go home, Moore now was channeling the energy of the street into direct action - not just against Girard but against discrimination at the Post Office and private employers. The new approach he fashioned was more militant than King's Gandhi-inspired nonviolence. King's visit seemed a threat to all that.

At first, Moore urged King to stay away from Girard. Just four days before the visit, the NAACP chief lashed out at King as "a divisive force," adding: "His only purpose is to get headlines and money." In hindsight, historians don't doubt that Moore's outsize ego played some role in his outbursts.

But on the eve of King's arrival, Moore's cadre of youthful freedom fighters - the so-called "Young Militants" - helped to convince their leader that he should shift course and share a stage with the Southern minister, that they needed King's energy.

Richard Watson - a 19-year-old art student at the vanguard of the protests and now a curator at the African-American Museum of Philadelphia - said the King-Moore truce was inevitable, noting that the two men had similar goals despite different philosophies. He said Moore believed more in a confrontational direct action, that he didn't encourage violence but supported a "militant" way. Many of the protesters studied martial arts, said Watson, adding: "It means you have a right to stand your ground."

A whirlwind visit

With the Girard rally back on, King's visit here was a whirlwind, racing through impromptu rallies in African-American neighborhoods such as Hawthorne Square, the Raymond Rosen housing project, and South 13th Street. He visited the homes of key activists and supporters, black and white, addressed a mass meeting at Grace Baptist Church on North Broad Street and even met behind closed doors with the Chamber of Commerce of Greater Philadelphia.

At the main "Freedom Now" rally at 40th and Lancaster, King gave a speech that years later would be echoed by a disciple, the Rev. Jesse Jackson.

"I come here from the front lines of the civil-rights movement in the South to tell you, 'You are somebody,' " King said. "Let us have a sense of somebodiness. Don't let anybody make you think that you are not somebody."

Somebody who met King just a few minutes later would be Marian Pankey, 14, whose mom - Abigail Pankey, head of the Mantua Housing Committee - made lunch for the civil-rights leader and his entourage, while some 300 neighborhood gawkers crowded outside their brick rowhouse on Folsom Street.

While the grownups ate fried chicken and potato salad buffet-style, Marian Pankey and her four siblings took their plates to the front stoop but were invited back inside to hear King's brief remarks.

"His humility was just awesome," said Pankey, recalling how the perpetually exhausted King shook hands with the kids and patiently answered their questions.

But King reached for grandeur, not humility, when he finally delivered his speech in front of the segregated Girard campus, before a big crowd that whooped with gospel-style yeses and amens.

"The white children who attend this college are as much slaves as the black children who are kept out," King thundered.

But the trip also was marked by a kind of running philosophical debate between Moore and King over the growing militancy of the civil-rights struggle, with Moore reportedly telling the Girard crowd: "I am not nonviolent."

King delivered a rebuttal of sorts that night at Grace Baptist. "I still believe, my friends, that violence is not the way," he preached. As quoted in the Bulletin: "If the negro comes to the temptation of violence . . . unborn generations will suffer meaningless chaos."

In the end, the outcome of King's historic visit here was mixed. On one hand, Watson and other activists recalled, his Girard speech gave credibility to their uphill integration campaign, which they won after four more months of street protest and a court battle decided by the U.S. Supreme Court in 1968.

But equally important, King's conflict with Moore - who was elected to City Council in 1975 and died four years later - likely convinced him to take his Northern civil-rights campaign elsewhere: to Chicago, where King and his family lived for much of 1966 during a campaign that included clashes with working-class whites and finally a tepid deal with its mayor, Richard Daley.

Countryman and other historians say they can't help but wonder how Philadelphia might have changed if King had come here instead. "It was a huge missed opportunity," he said - although at the same time he suggested that the deindustrialization of the city and its racial divisions would have overwhelmed any leader, even King.

Literally minutes after meeting King and feeling on top of the world, Jordan found herself in police handcuffs - arrested by officers who said she and a friend had desecrated an American flag by carrying one upside down, a symbol of distress. The incident also made news - Jordan said she was portrayed as "a rabble-rouser" seeking to embarrass King. But Jordan - now a nurse at Thomas Jefferson University Hospital - and most of Moore's other "freedom fighters" went on to become community leaders or caregivers, as many once-closed doors opened for Philadelphia blacks.

The Girard fight, she said, was the turning point. Jordan said that people who "believed in justice and equality made those walls tumble down - nobody could believe it would happen. That gave people hope that we could do almost anything."