Getting the Fourth of July off from his job at a fruit packaging plant was difficult, but it was important to Ruben Perez because the holiday has become a part of his family's life.

"You're here for so long, you adapt to American ways and holidays. It's a part of me now," Perez, who immigrated from Mexico 22 years ago, said in Spanish as he grilled a picnic feast for his family at Detroit's Belle Isle park (search).

"Today is about our freedom. It's about learning a new heritage," said his 11-year-old son, Edward.

They were among the millions of Americans celebrating the Fourth from beaches to backyard barbecues, at concert venues and elsewhere.

Millions gazed skyward from waterfront spots and rooftops throughout New York City on Monday night at the Fourth of July fireworks display billed as the nation's largest.

"It's awesome," said Shannon Ashenfelter, 24. "I've never seen so many fireworks before in my life."

The 30-minute display, sponsored by Macy's, featured 35,000 shells launched from several barges. In honor of the city's pending bid to host the 2012 Olympic Games (search), the display included symbolic gold, silver and bronze waterfalls and red apples representing the Big Apple. New York will find out on Wednesday whether it will host the Olympics.

In Boston, hundreds of thousands of revelers dashed to the banks of the Charles River to get prime viewing spots for the annual Boston Pops concert (search) and fireworks show. Organizers expected more than 300,000 people to gather along the Esplanade, which extends for three miles along the river.

"It's nerve-racking until you get your tarp down," said Sarah Broughton, 31, of Somerville, Mass., who nailed down a front-row spot by getting in line at 10:30 p.m. Sunday to wait for the gates to open Monday morning.

Molly Sheedy, 55, and her husband had driven to Boston from Albany, N.Y., undaunted by this summer's high gasoline prices and expensive hotels.

"There's no better place to be," Sheedy said as she took in the city's historic sites dressed in flag-print apparel.

The holiday had special meaning for Andrew Lynch since he moved last year from New Mexico to Baltimore, where an attack on Fort McHenry during the War of 1812 inspired "The Star-Spangled Banner."

"It makes it more real to me. It's more exciting. I can envision it," Lynch said.

The day also held special meaning for 80 men, women and children from 36 countries who were sworn in Monday as citizens at Monticello, Thomas Jefferson's home in Virginia.

"This is a great day for me to be an American citizen," said Darya Salih Askari, who came to America from Iraq. "This is a great country."

In Miami Beach, Fla., a naturalization ceremony for six children kicked off that city's Independence Day celebration. "You feel like another person," said 14-year-old Misha Orosz.

Elsewhere, however, a firework show was called off at Pawtucket, R.I., because a misfiring shell set off other fireworks on the ground and caused minor injuries to several people the night before the holiday.

While the Fourth of July means picnics and family cookouts for many people like the Perez family in Detroit, the tradition at New York's oceanside Coney Island is competitive gluttony.

For the fifth straight year, 144-pound Takeru Kobayashi won the Nathan's Famous hot dog-eating contest. Kobayashi, 27, of Nagano, Japan, gobbled 49 dogs in 12 minutes.

The runner-up was 105-pound Sonya Thomas of Alexandria, Va., who set an American record by downing 37 hot dogs in the same 12 minutes. "My stomach doesn't hurt but my jaw is tired," she said.

Three shark attacks in the past two weeks along Florida's Gulf of Mexico coast — one of them fatal — didn't keep tourists away, but many stayed close to shore or out of the water altogether. In Texas, the beach at Sea Rim State Park in Sabine Pass, about 85 miles east of Houston, was closed Monday because five sharks were spotted during the weekend.

Far from their loved ones, troops serving in Iraq marked the holiday as best they could. At Al Asad Air Base, Marine Cpl. Traben Pleasant, 24, of Long Beach, Calif., quaffed a nonalcoholic beer and thought of home.

"This is my third July Fourth in Iraq," Pleasant said. "I miss my family and friends. At home, I'd be barbecuing on the beach with my girlfriend."