In Boston, large crowds were still expected despite security restrictions after the April 15 bombings, and revelers snagged early spots for the evening Boston Pops concert and fireworks show.
Among those at Boston's festivities was Carlos Arredondo, the cowboy hat-wearing marathon attendee who became part of one of the indelible images of the bombings' aftermath: helping rush a badly wounded man from the scene in a wheelchair, his legs torn to pieces.
Arredondo said the July 4 celebration - an event authorities believe the bombing suspects initially planned to target - is an important milestone in the healing process, not just for him but also those who were stopping to tell him their own stories of that day.
"I think there's no better place to be," said Arredondo, wearing his cowboy hat and a "Boston Strong" shirt in the marathon's blue and yellow colors.
Christopher Dixon, 48, of Nashua, N.H., brought his daughters and grandson to the Boston celebration for the first time, saying as military members practiced shooting cannon fire that he had no worries about security.
"It's safer today than in your own backyard, I think," he said.
Quincy resident Laurie Tetrucci has been coming to the show since she was a child, but she said this year felt different.
"I think we're just a little more aware," she said. "I think we're a little more appreciative and grateful. I think it means more."
Not everyone was welcoming the masses - Hermosa Beach, Calif., was ramping up police patrols after years of drunken and raucous behavior from revelers. Hartford, Conn., postponed fireworks because the Connecticut River was too high.
Nationwide, anti-surveillance protests cropped up in a number of cities on Independence Day with activists speaking out against recent disclosures that the National Security Agency has been secretly logging people's phone calls and Internet activity. In Philadelphia, more than 100 people marched downtown to voice their displeasure, chanting, "NSA, go away!"
But in Union Beach, N.J., which was destroyed by Sandy, residents had something to celebrate. The working-class town won a party and fireworks contest from the television station Destination America and USA Weekend magazine.
"It's wonderful. Everyone's been so depressed," said Mary Chepulis as she watched a local band perform on a stage that stood where the home next to hers had been.
Every July 3, she and her friends and family would stand on a deck packed with people, food and coolers and watch the fireworks. Next week, she'll find out if the grant money she'll receive is enough to rebuild the home where she lived for 15 years.