PHILADELPHIA — Pope Francis wrapped up the 10-day visit to Cuba and the U.S., celebrating Mass to hundreds of thousands before boarding a jet to head back to Rome.
The pope boarded a plane and departed a little before 8 p.m. Pope Francis expressed his gratitude to about 400 leaders of the World Meeting of Families, supporters and other volunteers who helped organize his trip to Philadelphia.
Vice President Joe Biden and his wife Dr. Jill Biden were among those at the airport sending Francis off as he prepares to board a plane to depart for Rome.
Before Pope Francis left, he led a massive ceremony dedicated to families for what organizers estimate will be more that 1 million people.
With a packed agenda, Pope Francis visited a Philadelphia prison where he spoke to inmates. He met with survivors of clerical sex abuse and has promised to hold accountable those responsible.
Speaking to U.S. bishops, Francis said sexual abuse can no longer be kept a secret. He says he promised to “zealously” protect young people and that “all those responsible are held accountable.”
Hundreds of thousands of people gathered at the Benjamin Franklin Parkway for the papal parade before the Mass. During the parade, he exited the popemobile to kiss at least a dozen babies and also visit a “knot grotto” that is based on one of his favorite favorite paintings.
During the Mass, Pope Francis said everyone should be open to miracles of love for the sake of families around the world. His remarks came during the homily of the Mass.
Pope Francis left New York City to Philadelphia on Friday.
Before leaving from John F. Kennedy Airport, he stumbled a bit as he walked up the plane’s steps, but quickly recovered, and waved goodbye from the door and again from the plane through a window before the jet soared into the sky toward Philadelphia, where he will visit through Sunday night.
With a Mass Friday night for 18,000 people in a New York City arena, Pope Francis wrapped up a day that took him from the global spotlight of the United Nations to a classroom where he got impromptu coaching from a fourth-grader on using a touch screen.
He concluded the service with the customary “go in peace and serve the Lord” and added, “Please, I ask you, don’t forget to pray for me.”
During a visit that started Thursday, he attended evening prayers at St. Patrick's Cathedral, addressed the U.N. General Assembly and attended an interfaith service at the Sept. 11 museum at ground zero.
He also visited a school set amid public housing in East Harlem, took a processional drive through Central Park and, finally, presided over Mass at Madison Square Garden.
In his homily, Francis praised big cities for their diversity and culture but is warning that they can also make their people feel they don't belong, shunning them and treating them like second-class citizens.
Francis emphasized a point he has made throughout his U.S. trip: the need to welcome foreigners and marginalized people.
In his homily he also cited "children who go without schooling, those deprived without medical insurance, the homeless, the forgotten elderly."
He says God "frees us from anonymity, from a life of emptiness and selfishness." He also says, "God is living in our cities," and so is the church.
Earlier, in one of the most dramatic shows of affection during his U.S. trip, Pope Francis was greeted by scores of thrilled East Harlem school children during his visit to the Our Lady Queen of Angels School. The pontiff gamely posed for photos, patted the children on the head and hugged well-wishers who couldn't believe they were in his presence.
Inside the school, the children greeted him with the song "The Prayer of Saint Francis." The pope then chatted with the children in a classroom as dignitaries included Timothy Cardinal Dolan, Gov. Andrew Cuomo and Sen. Charles Schumer looked on. The children also made presentations to the pope, including one on the environment, one of the issues that's near and dear to his heart.
Earlier, Pope Francis brought his message of peace, humility and compassion to world leaders during a speech at the United Nations and lead a powerful multi-faith prayer service at the Sept. 11 Memorial Museum before he's set to meet with young students in East Harlem and participate in a Mass at Madison Square Garden.
The speech marked the largest gathering ever of world leaders in the 70-year history of the United Nations.
"I thank you, each and all, for your efforts in the service of mankind," he said as he began his historic address.
The pope said there is a "right of the environment" and that humankind has no authority to abuse or destroy it.
Hoping to spur concrete action at upcoming climate change negotiations in Paris, Francis accused the world's powerful countries of a "selfish and boundless thirst" for money. He says that has led them to destroy the planet and impoverish the weak and disadvantaged.
He also condemned human trafficking and the drug trade, and advocated a respect for life in all its forms and stages.
Officials took a peek at the message he left in the visitors' book.
The handwritten note in English was a simple but profound message for the world body, and perhaps for the global community at large.
"May the Almighty bless this assembly, and may its service to the international community be marked by fraternity, solidarity and justice. Francis."
After the somber and slightly weary-looking pope finished writing it, he allowed a brief smile, removed his glasses, stood and moved on to a full day ahead.
From there, he headed downtown to the 9/11 Memorial and Museum at the World Trade Center for a multi-faith service. Arriving at the World Trade Center, Francis prayed over and blessed the reflecting pool that marked the spot where thousands died in the 2001 terror attacks. He also met with families of 9/11 victims and the first responders who rushed to the site that day.
The pontiff, 78, arrived in the United States Tuesday evening for the first time as leader of the world's 1.2 billion Catholics and for the first time in his life.
So far, the Holy Father has addressed Congress -- urging the nation's leaders to take action on climate change and called for an end to the death penalty -- and had lunch with the homeless in Washington, D.C., instead of meeting for a meal with elected leaders. In New York last night, he rode up Fifth Avenue in the popemobile to the cheers of thousands and the peels of church bells. He presided over a vesper's prayer service at St. Patrick's Cathedral in which he shared a message of tolerance and compassion.
After his Philadelphia trip on Saturday and Sunday, he returns to Rome Sunday night.
The Associated Press contributed to this story.