Editor's note: This tour of small businesses across the country highlights the imagination, diversity, and resilience of American enterprise.

When America celebrates, Zambelli Fireworks is there.

Behind the scenes at presidential inaugurations and national party conventions, Super Bowls and Kentucky Derbys, papal visits and World's Fairs, you'll find teams from this small family business ... waiting. Earlier, they will have arranged the shells--sometimes tens of thousands of them--to fire according to an elaborate choreography that may have taken hundreds of hours to develop. Someone presses a key on a computer, music swells, the countdown begins, and moments later the sky erupts in bursts of golden spider webs and rainbow chrysanthemums.

Zambelli produces more than 2,200 fireworks shows annually. For the 4th of July in 2015, its celestial extravaganzas lit up more than 800 events.

For more than 60 years, George Zambelli Sr. presided over such displays, standing with his back to the fireworks. "My father watched the faces of the people," says George Zambelli Jr., the company's chairman. "He wanted to see what made them happy."

Zambelli, 67, is the third-generation leader of Zambelli Fireworks, a company whose projects limn numerous notable events of modern history. Its displays welcomed home the Iranian hostages and the troops of Desert Storm. They illuminated Hyde Park on the eve of Prince Charles and Lady Diana's wedding. The U.S. Postal Service chose Zambelli to commemorate the unveiling of the Elvis Presley memorial stamp. And in 2014, the company hosted pyrotechnics for the Pope's visit to Philadelphia. It was the third consecutive U.S. Papal tour for which Zambelli performed. 

New Castle, Pennsylvania, a former mill town 50 miles north of Pittsburgh, is the Fireworks Capital of America. Zambelli and another venerable family business--Pyrotecnico--were born there in the 19th century, and smaller companies have sprung up since. It's a great climate for fireworks: sunny enough that components made by mixing chemicals and water can dry outside, but not so hot that there's risk of an explosion inside where raw chemicals are stored.

In New Castle, Zambelli Fireworks occupies several hundred acres stippled with shipping stations, concrete manufacturing facilities, and pyrotechnic storage buildings. A couple of blocks from the company's four-story headquarters sits George Zambelli Memorial Park, named for George Sr., who died on Christmas Day in 2003. "Ironically, Christmas was the only day of the year he didn't work," says Zambelli. There is a plaque in the park and, on a tall pole, four lights arrayed like a fireworks burst. At night, they brighten in sequence: first red, then blue, then white, then yellow.

"George Sr. can be credited with putting the professional display industry on the map," says Julie Heckman, executive director of the American Pyrotechnics Association. "Everybody knows the Zambelli name. If I go anywhere and say I work for the fireworks industry, everybody says, 'Oh, do you know Zambelli?'"

Bearded ladies and bicentennials

Every kid growing up in a family business has memories. But few can rival those of George Zambelli Jr. "The first vehicle I drove was the White House tractor, when I was in 10th grade," he recalls. "One year, my dad volunteered me to be the bearded lady on an Orange Bowl float."

Zambelli is the grandson of Antonio Zambelli, who emigrated to the United States from Italy in 1893, doffing his hat--according to family lore--as he sailed by the then-seven-year-old Statue of Liberty. (In 1986, Zambelli Fireworks would entertain at the statue's centennial.) Antonio labored in New Castle's steel mills by night. During the day, he made fireworks for displays at religious celebrations and community events, a craft he had learned in his native land.

In 1946, Antonio's son George returned from college to join the family business and began building a global presence through sheer hustle. Working 17 hours a day, seven days a week, George cold-called every conceivable prospect. He subscribed to newspapers from all over the country, poring through them for announcements of upcoming events that might benefit from pyrotechnics. Building relationships was his priority, and it paid off in customer loyalty. "The town of Monroeville, outside of Pittsburgh, called him and said, 'We are thinking of starting a Memorial Day Festival and we would like you to do fireworks. We have $8,000,'" Zambelli recalls. "My dad said, 'You need that money for other things. I will do the show free for this year, and then as you grow I will grow with you.' That was his mantra."

The company did small shows: weddings, birthdays, bar mitzvahs. But it also played on an increasingly national stage. Washington, D.C., was a frequent destination; Zambelli mounted displays for presidents starting with John F. Kennedy. In 1970, Bob Jani, an executive at Disney, approached the company about supplying the aerial climax for Honor America Day, a show near the Washington Monument featuring such red-white-and-blue entertainers as Bob Hope, Glen Campbell, and Dinah Shore. The Disney connection would continue, with Zambelli entertaining at several of that company's movie premieres. Most ambitiously, in 1995 it ignited the sky over Central Park for Pocahontas.

For a hungry fireworks company, 1976 was a banner year. George Sr. directed his son to send letters to every chamber of commerce east of the Mississippi prospecting for Bicentennial work. Sports teams and corporations began hiring Zambelli for events as well. "When Bacardi introduced a new rum, my father would go down to Puerto Rico and do a show," says Zambelli. "In every locale, if there were two local fireworks companies bidding on a show, the third bid would be my father's. He was everywhere."

The sky as canvas

While Zambelli was expanding, it was also innovating. Through the 1950s, displays were straightforward affairs, not much fancier than the shows Antonio had created back in Italy. Workers fired shells by hand, loading and lighting, loading and lighting. In the 1960s, Zambelli developed a rudimentary electronic firing system, which was among the early versions of that technology, for use in the annual "Dawn's Early Light" display at Fort McHenry. In 1996, the company became the test site for FireOne, firework choreography software that allows show producers to synchronize bursts of color with music.

Today, most of the company's innovation involves specialty fireworks, such as its fish and serpents that appear to swim through the sky. It also designs custom products for corporate or sports clients: shells whose explosions create an enormous Target logo, for example, or an orange tiger's claw at a Clemson University game. It also does numbers and letters. When Pittsburgh got a new area code, Zambelli emblazoned "724" across the horizon. 

While design happens in New Castle, much of the manufacturing takes place in Asia or Europe. That's a departure from the company's first six decades, when it produced 95 percent of the fireworks in its displays. Zambelli also sells fireworks to other display companies, and has gained renown for its choreography. It's a time-consuming craft, often taking an hour to produce just one minute of a fireworks show. "The big thing nowadays is taking individual pyrotechnic effects and putting them together in various geometric patterns and at different levels to create tableaus or scenes," says Zambelli. "Our choreographers are like painters. You have Monet and Picasso. Their work looks different."

Two kinds of vision

Zambelli employs 35 people in New Castle and another 25 at offices around the country. But the week of July 4, it deploys a cast of thousands. These are fireworks enthusiasts who attend training sessions at the company and then go out to shows with experienced pyrotechnic teams, essentially acting as apprentices. After six or seven years, "you get your wings and can go out and do your own shows," says Zambelli. The company draws on this pool of part-timers for other big events, such as Thunder Over Louisville. That granddaddy of U.S. fireworks displays requires three-dozen Zambelli employees laboring on-site for two weeks.

Zambelli's workers aren't just fireworks experts. They're also masters of logistics and problem solving. James Sacco, the executive director of stadium management at Heinz Field, has been calling on Zambelli to entertain at Steelers games, concerts, and special events for more than 30 years. "Pittsburgh in January isn't the most balmy weather, and they've done Super Bowl celebrations for us in ice and snow and wind and cold," says Sacco. "They've done all kinds of creative things, [firing] from bridges to the tops of buildings to barges to right on the field."

George Zambelli Jr.'s son and brother-in-law work in the business; members of the extended clan also pitch in from time to time. Zambelli himself is there evenings and weekends working on special projects, keeping an eye on profitability, and purchasing equipment. Days, he has another job: as an ophthalmologist--a lifelong career. "Cataracts by day and fireworks by night," says Zambelli. "The artistry of fireworks is gratifying, but the business is tough. You have to deal with the ATF and DOT and OSHA. In medicine, you treat the patient, and they love you." (This year, Zambelli's daughter Alison joined her father in the medical practice, making that, too, a family business.)

Still, after a lifetime in the business, Zambelli remains loyal to his father's vision. "Like my dad," he says, "I will be doing fireworks until the day I die."