"No matter how many times you attack us, we always come back," Secretary of the Navy Ray Mabus said at the amphibious assault ship's commissioning. "America always comes back. That's what this ship represents."
He spoke on a Manhattan pier where hundreds of Navy officers and sailors joined first responders and families of Sept. 11 victims.
"I hereby place the USS New York in commission," Mabus announced.
And with a long drum roll, the ship's crew was set on the first watch, obeying the order, as traditionally worded: "Man our ship and bring her to life!"
From atop the vessel, decked in red, white and blue bunting, black smoke rose into the chilly fall morning to signal that the USS New York was powered up. A loud cheer accompanied a flyover by Navy planes.
The 7½ tons of steel debris from ground zero had been melted down to form the bow of the USS New York as "a symbol of our unshakable resolve; this is a city built of steel," said Secretary of State Hillary Rodham Clinton, representing the Obama administration.
Clinton was a U.S. senator from New York before she became the nation's top diplomat.
She noted that many of New York's iconic structures were made from steel, including the Statue of Liberty and the Chrysler building.
"But the strongest steel of New York has always been in the spines of its people," Clinton said, calling New Yorkers "strivers and seekers, immigrants from every country, speakers of every language."
The ceremony was staged on the Hudson River pier that is home to the Intrepid Sea, Air & Space Museum - against the backdrop of the new vessel docked at the next pier.
Among the dignitaries were newly re-elected New York Mayor Michael Bloomberg, New York Gov. David Paterson and the USS New York's new skipper, Cmdr. Curtis Jones.
A native of Binghamton, N.Y., he will oversee a crew of 360 sailors on a vessel transporting up to 700 Marines to war zones and humanitarian missions.
The $1 billion warship was built near New Orleans by workers who survived Hurricane Katrina.
"They had to rebuild their lives and their homes at the same time as they built the ship," said Irwin F. Edenzon, general manager for Northrop Grumman Shipbuilding-Gulf Coast, which built the USS New York.
The new ship is "about healing," said Mike Petters, president of Northrop Grumman Shipbuilding. "It symbolizes much of what is great about America and Americans."
Arriving in New York on Monday, the ship passed the World Trade Center for the first time and gave the site a rifle volley salute.
The Navy has named two of the USS New York's planned sister ships the USS Arlington, to mark the attack on the Pentagon, and the USS Somerset, named after the Pennsylvania county where United Airlines Flight 93 crashed.
Saturday's ceremony began with a moment of silence for the victims of the shooting at Fort Hood, Texas, where an Army major fatally shot 13 people and wounded 29.
The USS New York will be open to the public before returning to its home port of Norfolk, Va., on Thursday.