Last Updated Sep 25, 2015 7:14 PM EDT
NEW YORK-- Pope Francis celebrated Mass with a crowd of around 20,000 people at Madison Square Garden on Friday, culminating a busy day in New York City that included a visit to the 9/11 Memorial, an East Harlem school, an address at the United Nations and a procession through Central Park.
The 78-year-old pope was driven into Mass on a white golf cart waving to his thousands of admirers, including sick children and those with developmental disabilities, extending his hand out to bless many of them.
"Once in a lifetime, right? Once-in-a-lifetime visit," said one woman to CBS New York.
Pope Francis opened the Mass by saying, "We are in Madison Square Garden -- a place synonymous with this city." Also beginning the Mass was CBS News' "Sunday Morning" correspondent Mo Rocca delivering a scripture reading in Spanish.
Pope Francis concluded Mass by saying, "Don't forget to pray for me," evoking loud cheers and applause.
Earlier in the day, Pope Francis arrived outside of Our Lady Queen of Angels school in East Harlem, where he was met by excited students holding up rosaries and flags and cellphones so they could snap photos and take selfies with the beaming pope.
As Pope Francis entered a classroom at Our Lady Queen of Angels school, a group of children gathered from four different local Catholic schools greeted him in song. They belted out the lyrics to, "Make Me an Instrument of Your Peace," known as the Prayer of St. Francis.
The grinning pope encouraged the students to sing louder, one of those students being 9-year-old Nicholas Marronaro.
Before meeting the pope, Nicholas told CBS News he thought the pope would be easy to talk to. Nicholas is one of the students who was given the opportunity to greet the pope when he visited his school.
Prior to the pope's visit, the principal of Our Lady Queen of Angels, Joanne Walsh, told CBS News she was getting more nervous as Pope Francis' arrival approached.
"We're sort of a speck in this big world, and to think that Pope Francis is coming here ... I think it's still beyond my comprehension," she said. "I don't think it's going to crystallize until the day he arrives."
But crystallize it did. And during the pope's visit to her school, Walsh stood side-by-side with the Holy Father.
"Keep dreaming about living with joy," the pope told a group of students and faculty gathered to hear him speak. "...you have the right to dream and I am really happy that you...you can find the discipline to do it."
After visiting East Harlem, Pope Francis made his way to Central Park for a procession where he was greeted by an enormous crowd of around 80,000 people, some who waited hours to catch a glimpse of him in his popemobile.
"As he passed by, you passed a cool, refreshing peace, as if he were spreading a huge blanket of peace through the crowd," Ruth Smart of Brooklyn said of the procession to the Associated Press. "Even though the crowd exploded in a roar, it was pure joy."
From Central Park he went to Madison Square Garden.
New York marks the second U.S. city he has traveled to, and the third day of his U.S. tour.
Pope Francis kicked off his first full-day in New York with an address to the United Nations General Assembly. During his speech, which was delivered in his native Spanish and then translated into English, the pope touched on issues such as the war on drugs, climate change and the, "urgent need to work for a world free of nuclear weapons."
Pope Francis then participated in a inter-faith prayer service at Ground Zero, alongside leaders of various religions.
Before the service, the pontiff was seen silently praying at Ground Zero over the names of those killed at the Twin Towers site. He then placed a white rose on the 9/11 Memorial, before meeting with families of Sept. 11 victims.
Pope Francis first arrived to John F. Kennedy Airport in New York City on Thursday evening on his jet, given the name, "Shepherd One." The pope was greeted by Catholic Church dignitaries and a cheering crowd. He then proceeded to St. Patrick's Cathedral on 5th Avenue for Vespers.
On his final day in Washington, D.C., Pope Francis gave a historic address to Congress, calling on lawmakers to tackle issues such as the Syrian migrant crisis and climate change and called for an end to the death penalty.
Pope Francis departs New York on Saturday morning, where he will finish the last leg of his U.S. tour in Philadelphia.
His two days in Philadelphia include celebrating Mass at Cathedral Basilica of St. Peter and Paul, a visit to Independence Mall and a visit to Curran-Formhold Correctional Facility.