NEW YORK -- Pope Benedict XVI celebrated Mass and American Catholicism in Yankee Stadium on Sunday, telling his massive U.S. flock to use its freedoms wisely as he closed out his first papal trip to the United States.
Benedict beamed before a crowd of 57,000, hours after making a solemn stop to pray at the site of the Sept. 11 terrorist attacks on the World Trade Center.
He called the Mass "a summons to move forward with firm resolve to use wisely the blessings of freedom, in order to build a future of hope for coming generations."
And he repeated a core message of his six-day pilgrimage -- that faith must play a role in public life, citing the need to oppose abortion.
The unwavering truth of the Roman Catholic message, he said, guarantees respect for the dignity of all, "including the most defenseless of all human beings, the unborn child in the mother's womb." The crowd applauded the line.
Worshippers filled the seats, chanting, clapping and waving white and yellow handkerchiefs in the Vatican's colors as the white popemobile pulled in.
Outside the stadium, two dump trucks filled with sand blockaded 161st Street before Mass, an extra level of security along with the heavy police presence. Pilgrims without tickets pushed up against metal police barricades, hoping to get a glimpse of the arriving pope.
Inside, ad-splashed outfield walls were draped in white with purple and yellow bunting. A white altar perched over second base, and the papal seal covered the pitcher's mound.
Benedict praised the U.S. church, which has 65 million members, saying that "in this land of freedom and opportunity, the church has united a widely diverse flock" and contributed greatly to American society.
Earlier in the morning, the pope blessed the site of the terrorist attacks and pleaded with God to bring "peace to our violent world."
The visit by Benedict to ground zero was part of a trip marked by festive crowds, such as the one at Sunday's Mass.
Benedict was driven in the popemobile part-way down a ramp now used mostly by construction trucks to a spot by the north tower's footprint. He walked the final steps, knelt in silent prayer, then rose to light a memorial candle.
Addressing a group that included survivors, clergy and public officials, he acknowledged the many faiths of the victims at the "scene of incredible violence and pain."
The pope departed on a special airliner after a farewell ceremony hosted by Vice President Dick Cheney, with Democratic presidential hopeful Hillary Rodham Clinton and President Clinton in attendance. "May God bless America!" the pope said before departing.