In 1703 my great-grandmother, Dorothy Jones Cantril, was brought before the court in Philadelphia. Her crime? ‘Masking in men’s clothes and walking and dancing in the house of John Simes after 9 or 10 o’clock at night.’ For her wickedness, Dorothy was fined £1 and went down in family history. But the god-fearing town where merrymaking was once an offence has become a vibrant city of culture and cuisine, a place where my cross-dressing Quaker great-granny could truly kick up her heels.

You can’t escape history in Philadelphia. Few cities in America have roots so deep. It was founded in 1682 by William Penn, an English Quaker who, in payment of a debt from the Crown, had received a tract of land in the New World nearly as big as England itself. He envisioned the colony as a ‘holy experiment’, a place where people could live free from religious persecution, and named it Philadelphia, Greek for ‘city of brotherly love’.

Settlers flocked to this liberal haven, Penn pocketed the rents, and if the colony never became quite the Utopia it was meant to be, it attracted patriots like Benjamin Franklin with visions of their own. Penn himself visited only twice and spent less than four years here. But within a century his ‘greene countrie towne’ witnessed the signing of the Declaration of Independence, the Constitutional Convention, and served as the first capital of the newly formed United States from 1790 to 1800.

Throughout much of the 19th century, Philadelphia was the ‘Athens of America’ and dominated the cultural life of the nation. It was an industrial powerhouse until well after World War II. Despite its illustrious past, in recent times America’s fifth-largest city has never enjoyed the cachet of other metropolises on the east coast. It got lost somewhere in the 1960s, bogged down by urban blight and an exodus to the suburbs. Its renaissance began in 1992 with the election of former Mayor Ed Rendell, a latter-day Penn whose civic programmes drew people back to the centre of this grand city. And so Philadelphia entered this millennium reborn as one of America’s most exciting cities, a multicultural mêlée of music, museums and fine cuisine.

Philadelphia’s true character is often overshadowed by its handsome colonial backdrop and numerous historical sites. It has always been a port, an immigrant city, with a mingling of creeds and cultures from around the world. Today there are over 100 neighbourhoods, many of which retain their ethnic character. Quaker Philadelphia was also the first US city to abolish slavery, drawing many black residents, and African-Americans make up 40 per cent of the population. This cultural blend gives the city its vibrancy.

In Philadelphia you can sample the breadth of the American experience. You can munch pretzels on a street corner, or dine in one of the country’s finest restaurants; hear the Philadelphia Orchestra or hot jazz and blues; shop in posh department stores or the Italian market. And, it’s easy to get around.

The city stretches between the Delaware and Schuylkill (pronounced ‘Skool-kil’) rivers, laid out on an orderly grid by William Penn himself and anchored by four town squares. A fifth central square is now covered by the massive hulk of City Hall, which forms the hub of Center City, bisected by the two main thoroughfares of Broad Street running north—south, and Market Street running east—west down to the historic waterfront district along the Delaware. You can stroll river to river in little more than an hour’s time, or use the excellent public transport network.

The best way to explore Philadelphia is from the roots up, and I set about finding mine in the Old City cultural district. My Welsh-born ancestor, Dorothy Jones, arrived here in 1682 at the age of 10, and a decade later married Richard Cantril, a brick-maker from Derbyshire. Family tradition holds that he built the first brick house in the city, at the corner of what is now Arch and Front streets. The house, of course, is long gone, and its waterfront view obstructed by a concrete wall that shields a motorway, but half a block north is Elfreth’s Alley, dating from 1713 and the oldest continually inhabited street in the country. Though this cobbled alley of 33 tiny brick row houses looks like a movie set, all are private homes save for the Elfreth’s Alley Museum, a window into life in the early 18th century.

The Old City is dotted with colonial gems. Sceptics may dispute whether Betsy Ross sewed the first American flag, but her house is an authentic depiction of working-class life at the time of the Revolution. Also on Arch Street is the US Mint, where you can watch high-speed machines cranking out the nation’s coins, and the Friends (Quaker) Meeting House. Graceful Christ Church with its pointed white steeple, arched windows and simple interior is one of the finest colonial structures in the city, and you can rest awhile in the pew where George Washington worshipped.

In 1693, my ancestors built a new home at 3rd and Market streets. Had they been a few decades later, they would have been neighbours with one of the city’s most illustrious figures. Boston may claim John Kennedy as its native son, but it lost Benjamin Franklin to Philadelphia. Franklin arrived here a penniless teenager in 1723, and became a printer, scientist, philosopher and statesman, the master builder of both the city and the young nation. He founded America’s first library, hospital and fire company, and invented, among other things, bifocals and the lightning rod. Like Kennedy, he had a vision for his country — and a string of extramarital affairs to which an adoring public turned a blind eye.

Franklin Court, off Market between 3rd and 4th streets, is the site of his last home, which he began building in 1763. It was demolished long ago, but in its place is the striking ‘ghost house’, a steel-frame outline of the original structure. Also here are a working post office which uses a ‘B. Free Franklin’ postmark, an 18th-century printing shop and a fascinating underground museum which depicts Franklin’s life and work.

Behind Franklin Court along Chestnut Street is Independence National Historic Park. These leafy acres harbour the famous Liberty Bell, which sounded at the first public reading of the Declaration of Independence in 1776. You can tour Independence Hall where the document was signed, and stroll in quiet contemplation past handsome colonial buildings, several of which are open, such as Carpenter’s Hall and the Second Bank of the United States, an outstanding Greek Revival edifice that houses a portrait gallery.

There’s more to the Old City than history, however. It’s the latest dining Mecca, with a host of hip restaurants such as Fork, Paradigm and Novelty. Art galleries have proliferated in the old factory buildings north of Market along 2nd, 3rd and Cherry streets, and are open late on the ‘First Fridays’ of each month.

Walkways at the end of Market and Walnut streets lead to Penn’s Landing, where William Penn first stepped ashore. This stretch of the Delaware waterfront is a nighttime hot spot and, in summer, a festival pier with free weekend concerts, the RiverBlues Festival, Jambalaya Jam and other events. You can also take a river cruise or tour the Independence Seaport Museum.

My Cantril ancestors left Philadelphia soon after that unfortunate masquerade party, but had they stayed their children might have moved south to Society Hill, now one of the most charming areas of the city. You can tour grand colonial mansions such as Powel House and Physick House, admire the 18th-century homes along Spruce and Delancey streets or wander into cobbled alleyways and hidden courtyards lined with ‘Trinity’ houses — three-storey homes with only one room on each floor. The district also has many historic churches.

By contrast, South Street, its southern boundary, is the self-styled hippest street in town. The six blocks west from Front Street are crammed with some 300 punky, funky, brightly painted boutiques, galleries, cafés and restaurants, and it’s lively day and night. The surrounding streets contain some of the finest specimens of Philadelphia’s Mural Arts programme. It began as a means of stamping out graffiti, and today nearly 1,900 murals adorn homes and businesses throughout the city. You can see them on a trolley tour, tel: (215) 568-5245 for details.

West of the Historic District, City Hall is the focal point of Center City. Built in Second Empire style with a massive central tower rising 548 feet high, it is the largest municipal building in the country. Atop the tower is a bronze statue of William Penn by Alexander Milne Calder. For most of the 20th century no one dared build higher than this beloved landmark, until the Liberty One tower broke rank in 1987, signalling change. The view over the city from the observation deck at the statue’s base is magnificent, and you can see the ornate public rooms on a guided tour.

The modern sculptures west of City Hall, such as Claes Oldenburg’s Clothespin, are products of a city ordinance that designates one per cent of new construction costs to fund public art. On JFK Boulevard, next to Robert Indiana’s famous LOVE artwork, is the Philadelphia Visitors Center, where you can pick up maps and information (it will move to the new Gateway Regional Visitor Center at Independence Mall at the end of this year).

Here too is the start of the Benjamin Franklin Parkway, a mile-long thoroughfare running diagonally through the Parkway Museums district. At the base of this broad, flag-lined boulevard is Logan Square, with the glorious Swann Memorial Fountain whose reclining nudes represent the city’s three rivers. On its east side is the Cathedral of Saints Peter and Paul. On the west are the Franklin Institute, an outstanding science museum that also contains the Benjamin Franklin National Memorial; the Academy of Natural Sciences with its dinosaur hall and butterfly habitat; and the Please Touch Museum for Children.

Further up the parkway the Rodin Museum contains the largest collection of the sculptor’s works outside Paris. Crowning the top of the hill is the city’s neoclassical jewel, the Philadelphia Museum of Art, reached by the monumental flight of stairs that Sylvester Stallone (a Philly native) ran up in the film Rocky. Though dozens of visitors mimic this feat, the view from the top back towards the city skyline is equally breathtaking if you take your time. The museum’s collection is one of the nation’s finest, spanning 2000 years of art from Europe, Asia and America. Shaker furniture, French Impressionist paintings and a 16th-century Hindu temple are among the many highlights.

North of City Hall on Broad Street are two more venerable institutions. The Masonic Temple (1868) contains seven lodge halls magnificently decorated in different styles from Egyptian to Oriental. The ornate Pennsylvania Academy of the Fine Arts is the nation’s oldest art school and museum, and displays leading American artists from Charles Willson Peale to Thomas Eakins.

South of City Hall, Broad Street becomes the Avenue of the Arts, passing a parade of world-class cultural venues that include the Wilma and Merriam theatres, the Arts Bank, the Academy of Music and the new Kimmel Center for the Performing Arts. To either side are two of Philadelphia’s most characterful neighbourhoods. The Washington Square district is a colourful mix of 19th-century homes, historic theatres and museums such as the Atwater Kent museum, and the shopping enclaves of Antiques Row and Jewelers’ Row. Rittenhouse Square, while no longer the sole preserve of Philadelphia’s upper crust, is a prestigious area of handsome homes and upmarket shops. The elegant restaurants along Walnut Street are among the city’s finest.

East of City Hall on Market Street, the former John Wanamaker department store, now Lord & Taylors, recalls Philadelphia’s glory days with its lofty Grand Court and 30,000-pipe organ which is still played twice daily. Philly is definitely the place to do some shopping as there is no sales tax on clothing, and stores abound in Center City, particularly along Market Street.

The most delightful browsing is in Reading Terminal Market, tucked beneath the enormous Pennsylvania Convention Center which occupies a former train shed. At this bustling food market you can sample quintessential Philly delights from chewy pretzels to scrapple, cinnamon rolls and Pennsylvania Dutch treats. The amazing array of foods symbolise Philadelphia’s rainbow of nationalities. Foodies and people watchers should also make an excursion to the outdoor Italian Market in South Philly, one of the largest in the world.

East of the Convention Center on Arch Street is Chinatown. On my last night in Philadelphia, at Joe Poon’s Asian Fusion restaurant, I met a modern-day immigrant who epitomises what the city is all about. Born in Hong Kong, Joe Poon came to Philly via Nottingham and learned English from the menu while working as a waiter. Today, he has three restaurants of his own and is one of the city’s most enthusiastic chefs. After a stroll around Chinatown, we hopped in Joe’s car and he took us to see the Liberty Bell at night, Boathouse Row lit up with fairy lights along the Schuylkill, and finally to the Italian district in South Philly. Here two rival grills, Pat’s King of Steaks and Geno’s, face off under bright lights on opposite corners. They both serve cheesesteak, a simple sandwich of chopped beef, grilled onions and melted cheese that is Philadelphia’s most famous food. But locals are passionate about whose cheesesteak is best.

Even though we’d feasted on lobster and Peking duck at Joe Poon’s restaurant, he insisted we go to Pat’s because ‘you can’t leave Philadelphia without trying a cheesesteak’. That’s fusion, Philly style.