The pope’s motorcade then left the memorial. Crowds gathered along his route uptown to his apartment; a woman, tears streaming down her face, hoisted a baby on her shoulders. All day, enormous crowds lined sidewalks behind metal barriers and tall fences, straining for a glimpse of the figure in white.

“They are cast off by society, forced to live off what is discarded and suffer unjustly from the consequences of abuse of the environment,” Francis said. “These phenomena are part of today’s widespread and quietly growing ‘culture of waste.’ ”

Francis sought out some of those faces on a day of grand pageantry and small gestures that brought him before the relatives of the fallen at the footprints of the twin towers and, hours later, the upturned smiles of East Harlem schoolchildren not yet born the day those buildings were destroyed.

He spoke of that divide often during the day, from his first remarks before the United Nations General Assembly, where he called for respect for “those considered disposable because they are only considered as part of a statistic,” to his closing homily’s observation that “big cities also conceal the faces of all those people who don’t appear to belong, or are second-class citizens.”

“New York City firefighters walked into the crumbling towers, with no concern for their own well-being,” he said. “Many succumbed. Their sacrifice enabled great numbers to be saved.” He called the site “a place of saved lives, a hymn to the triumph of life over the prophets of destruction and death.”

The pope walked through the museum, past the relics and totems that have become indelible images from that day 14 years ago, like the hulking section of the trade center’s foundation wall, the “slurry wall,” and the “last column,” an icon covered with pictures and truck and unit numbers from the city’s firehouses and police precincts.

Francis turned at that point, meeting a long line of relatives who shared memories of those who had died on Sept. 11. He listened, often clutching an outstretched hand, and once patting a little girl’s head. He entered the museum and its Foundation Hall, where a multifaith ceremony of striking breadth — representatives of Judaism, Islam, Hinduism, Sikhism and Christianity — heard him eulogize those who died trying to rescue others.

It was a false alarm. The first of many. But their enthusiasm was undimmed.

, on his first visit to New York City, will use his position as the leader of a 2,000-year-old institution with 1.2 billion followers to push for global change even as he seeks to present himself as a simple man who is in touch with the crowds that will line the streets to cheer his every move.

In spite of the tight ring of dark-suited security that surrounded the pope at all times, many were allowed a closer look. Among them: a New York police officer, Terrance McGhee, in a wheelchair at the World Trade Center site, whom Francis stooped to greet; dozens of children outside Our Lady Queen of Angels in East Harlem, who waved cellphones as Francis gave head-pats and high-fives; the day laborer at the Garden Mass, a medal under his shirt of St. Jude, the patron saint of lost causes; the babies held out for a blessing in the Garden.

From the moment Francis’ plane touched down at John F. Kennedy International Airport on Thursday evening, crowds gathered to cheer and wave or simply take in the spectacle. As the pope made his way along Fifth Avenue, standing in the back of his specially outfitted popemobile, thousands pressed against barricades, cameras and smartphones held high in hopes of capturing the moment.

“Here grief is palpable,” he said.

“Together we are called to say ‘no’ to every attempt to impose uniformity and ‘yes’ to a diversity accepted and reconciled,” he said.

Damon Winter/The New York Times

There, he paused for a long moment of silent reflection, gazing down into the pool of cascading water, which, from the visitor’s vantage point, has no visible bottom. He looked at the names of the victims on the panel at his fingertips, one of many panels at the site that, together, bear thousands of names: Boyle, Woods, Nguyen, Lynch. The falling water brought the only sound. He and Cardinal Dolan each left a white rose on the panel.

And he called for peace. “Peace in our homes, our families, our schools and communities. Peace in all those places where war never seems to end. Peace for those faces which have known nothing but pain.”

That theme, that “God is living in our cities,” provided an apt conclusion to a day spent navigating New York’s complicated fabric of rich and struggling. It was the pope’s first visit to the city, where the longtime hum of the machines of commerce and prosperity has brought the very excesses he has spent his papacy pushing against. It was impossible to ignore, behind the rows and rows of well-wishers who packed Central Park’s broad meadow, the soaring columns of skyscrapers with penthouses that are home to many of the world’s wealthiest people.

“In big cities, beneath the roar of traffic, beneath the rapid pace of change, so many faces pass by unnoticed because they have no ‘right’ to be there, no right to be part of the city,” Francis said in a Mass before 20,000 at Madison Square Garden. “They are the foreigners, the children who go without schooling, those deprived of medical insurance, the homeless, the forgotten elderly. These people stand at the edges of our great avenues, in our streets, in deafening anonymity.”

It was also a respite from nagging thoughts that society’s ills will remain after he has left New York, the middle leg of a United States visit that began in the capital and ends on Sunday.

“He’s coming!” yelled Jeshani Guevara, 39, dragging her 4-year-old with her 12-year-old close behind as she ran up Fifth Avenue.

When Francis enters Central Park on Friday evening, some 80,000 adoring fans will have waited hours to catch a glimpse of the man after having secured tickets in a city-sponsored lottery.

Around the park, residents in the towers of privilege, where the price of an apartment has topped $100 million, can take in the show from high in the sky.

In an outsize city known for its brash self-confidence, tens of thousands of its residents prepared on Friday to celebrate a man who is known for his humility.

The pope, speaking in Spanish, made his remarks in the underground chamber where the building’s foundation still stands, praying with hundreds of diverse religious leaders and urging them to be “a force for reconciliation, peace and justice.”

His words were calibrated, but his message was clear.

In seeking to strengthen ties with leaders of other faiths, Francis is continuing the path of his predecessors and deepening a commitment the Roman Catholic Church first made 50 years ago with the Second Vatican Council and the declaration “Nostra Aetate.”

The pope toured Manhattan beginning with an address at the the United Nations General Assembly and ending with an evening mass at Madison Square Garden.