American dream: Simon Calder follows the road to independence

America's archetypal thoroughfare? You can come up with plenty of contenders for Main Street, USA. Avenues of hopes and broken dreams such as Broadway in Manhattan or Hollywood in California; the mercantile mile of middle America known as State Street, Chicago; or Las Vegas Boulevard, a strip that mangles cultures into cartoons. But I suggest instead a road that leads you to the soul of the nation: Massachusetts Avenue. Follow this unusually meandering highway for 20 miles, and you will understand much more about the world's only superpower - and experience a sequence of unexpected treats.

Unless you are a punctilious collector of great arteries, do not delve too deep in search of the start of "Mass Ave", as everyone seems to call it. The road originates deep in the southern suburbs of Boston. On its course through the Massachusetts capital, it manages to bypass the entire colonial core of America's most alluring city. So far, so unpromising - so instead pick it up at a subway station with the most melodic name in mass transit: Symphony. Ask the conductor where to get off.

Emerge from the platform on the east side of Mass Ave, and you may wonder if the "T" (as the subway is known) has whisked you across the ocean. The sight that confronts you across a limestone plaza is a glorious ecclesiastical confection. The framework is based on Istanbul's Hagia Sophia, while the dome borrows elements from St Peter's in Rome and the Duomo in Florence. The temple is the Mother Church of Christian Science, this year celebrating a century since its completion.

Symphony, the name of the station at the corner of Mass Ave and Huntington Avenue, has nothing to do with this well-tuned creation. It signals Symphony Hall, the elegant auditorium that houses the Boston Symphony Orchestra. So well funded is the BSO that, were its annual budget redistributed among the citizens, every Bostonian would pick up $135 (£75). But no one would dare suggest such a thing so long as the orchestra maintains its standing as one of the world's leading ensembles. The auditorium itself vies only with Amsterdam's Concertgebouw for the title of finest acoustics.

Major Henry Lee Higginson, the founder of the orchestra, made an unlikely benefactor for classical music. "I have no talent for music," he once asserted. Yet he devoted most of his life to building America's original orchestra (which premiered in 1881), and later the first symphony hall, enlisting a professor of physics, Wallace Clement Sabine, to dictate the architecture according to the principles of acoustics.

In summer, though, the strings and horns must take their chances in the open air. The orchestra (minus the virtuosi) transforms itself into the Boston Pops, and will play beside the wide, serene Charles River next Tuesday, Independence Day.

Freedom; liberty; emancipation: the Fourth of July celebrates all these virtues, focusing on the ousting of a despised occupying power. Not from Cuba, nor Vietnam, nor Iraq. The reviled target for 18th-century insurgency in the Massachusetts Bay Colony was Britain. The imperial power sought to control and exploit the first proper city on the eastern seaboard.

Ironically, the first Europeans settlers were * * religious refugees: Puritans, seeking a promised land untainted by baser human instincts. Milk and honey may have flowed freely in their new, improved England, but the third essential to life - tea - was subject to imperial whim.

The Tea Act of 1773 was not, as is commonly thought, a law to restrict and raise the price of the precious leaves. Rather, it was a necessary device to deal with a tea surplus that had been accumulated by the British East India Company, allowing the near-bankrupt enterprise to ship it direct to the colonies. But the Bostonians, suspecting imperial shenanigans, demanded that the three ships despatched by George III leave the city's harbour without unloading their precious cargo.

In the last month of 1773, the height of rebellion involved around 50 men disguised as Mohawk Indians boarding the Dartmouth, Eleanor and Beaver, and emptying the tea chests into the water. While hardly on a par with suicide bombings, it was enough to unleash legislation that trampled on the human rights of the colony's citizens.

Today, you could board the Boston Tea Party Ship and Museum for what purports to be an action replay - but when I tried it, the visitor was merely invited to hurl a plastic box labelled "tea" into the harbour, whereupon it was winched up for the next punter. Far better to embark on the "What happened next?" trail.

The best way to spend a summer's day in Boston is to leave it - temporarily, at least. A rented bicycle will allow you to drift downhill from Symphony Hall, past the legendary Wally's Bar (blues and/or jazz, every day of the year) and across the tangle of road and rail arteries that funnel people away to less exciting parts of America.

You could dally for a while along Beacon Street, an artful string of cafés, boutiques and galleries. But instead keep the morning sun on your back, and cruise over the river. Crossing Harvard Bridge, your eye is sure to stray along the arc of the riverbank to the jumbled core of the city.

Once on the north shore, pause to recalibrate. First, your architectural sensors can revert to European, and specifically British, mode: Cambridge, Massachusetts pays effusive homage to its namesake. Here, the red brick is used to majestic effect to create towers of learning interspersed with cosy communities. Next, ratchet up your intellect: Cambridge is home to Harvard, the Massachusetts Institute of Technology and the sharpest brains in America.

Massachusetts Avenue threads through the middle of Cambridge, providing a cross-section of a place that, you may suspect, secretly yearns to be Europe. Harvard Square has far more in common with a continental plaza than the commercial brashness of Times Square in New York or Union Square in San Francisco.

Middle America is just along the road, though. Massachusetts Avenue soon sheds its poetic pretentions and becomes a prosaic thoroughfare displaying all the spirit-stifling anonymity of Suburbia, USA: chain stores and car showrooms, enlivened by the odd funeral parlour. Average does have its advantages, though: shortly after the streetscape migrates seamlessly across the city limits into Arlington, the archetypal American diner appears on the left. Humanity is restored in a hubbub of hungry folk savouring delicious anticipation: you can peer from the chrome counter into the kitchen backstage, where culinary magicians turn rudimentary ingredients like eggs, bacon and potato into simple but irresistible feasts. The Arlington Restaurant and Diner is best visited alone, because only solo visitors can fully appreciate every nuance of theatre, fuelled by an unlimited supply of coffee (the events of 1773 mean that the Americans have never quite got the hang of tea).

Onwards and backwards: as your Avenue goes deeper into Massachusetts, the humdrum ends with a jolt. Lexington is a town that has not allowed the suburbs to encroach, thus preserving its heart - a curious triangle of lawn, presided over by a flagpole of skyscraping proportions.

Paul Revere, an early American patriot, is the closest America gets to a Che Guevara figure. On the night of 18 April 1775, he set off from Boston (where his house is now a top tourist attraction) to warn the local militias, called Minutemen, of an advance by a British column towards the town of Concord - where, military intelligence suggested, a stockpile of rebel arms had accrued. At Lexington he warned two fellow revolutionaries, Samuel Adams and John Hancock, to flee. The next day, the 700 British Redcoats arrived and confronted a small party of Minutemen commanded by Captain Parker. "Stand your ground," he ordered his 76 men. "Don't fire unless fired upon. But if they mean to have a war, let it begin here." Seven of the Minutemen who died at the de facto declaration of war are buried on what is now called Battle Green. This was the beginning of the War of Independence.

By now you are deep into the meadows and woodlands that seem set to ripple westwards forever - but you will get only a mile outside Lexington before the eight (or was it 10?) lanes of Route 128 roar in a torrent of hydrocarbons beneath you. Peace is soon restored on the other side of the bridge, where you have an appointment with war. The Minute Men National Historic Park is an example of how brilliantly the Americans can make the most of what a cynical European might regard as a superficial history. An area the size of Boston has been preserved as a memorial to insurgency.

Near the entrance, the headquarters building sets the heroic scene (as always, the victors write the history). An audiovisual presentation ranges from twee to compelling to melodramatic as it distils years of conflict into 25 slick minutes. British visitors for whom 1775 has none of the resonance of 1066 can pick up a basic history that will help bring the next stretch of the journey to life.

The British column set off from Boston with the aim of sorting out the restless patriots. They took the only road then available, a cart track that wriggles across terrain ranging from heathland to swamp. Today's visitor is elevated above the marshland on a boardwalk, and enlightened by some well-presented information bites at every turn. The Minutemen used the sorts of guerrilla tactics that have latterly returned to haunt the Americans, using well-concealed positions and picking off individual soldiers among the increasingly ragged and exhausted British column.

You may feel a little chronologically confused, because the British retreat took the same wayward path as the advance had done, and the bulk of the casualties were sustained on the way back to Boston. At Concord, though, the tricky tale should start to make sense.

Were you to blend of every preconception you have about New England style - simple clapperboard homes, an ambitiously neo-classical church, a village green and an air of contentment - the result would be Concord. Too tranquil, surely, to have been the scene where "the shot heard round the world" was fired, you could conclude. But wander a short way north and you find Punkatasset Hill, where the Yankee militias assembled to assess the much stronger British contingent.

The search for weapons of moderate destruction had fragmented the Redcoat force, and the Minutemen defeated the British at North Bridge. Ralph Waldo Emerson's "Concord Hymn" describes the event that gave the Americans faith in revolution. It centres on "the rude bridge that arched the flood" - now a polite wooden structure over a gently flowing stream - and celebrates the spirit "that made those heroes dare to die, and set their children free".

Any journey can be improved by making it a circuit rather than there-or-back-again, so you will want to return to Boston by a different route. Aim south, and you find yourself skirting Walden Pond - the surprisingly large lake that provided a waterside home for the writer Henry David Thoreau, and is now an ersatz seaside. The wooded shore serves as an inland alternative to the beach at Wonderland, as the last stop on Boston's ocean-bound subway is known. On summer weekends Walden Pond is so popular that prospective bathers and sunbathers are sometimes turned away.

Further down the thickly wooded road, a dazzling white sugar cube emerges. From a distance, that is what the Gropius House resembles. Closer inspection reveals it to be an émigré from 1930s Germany. Walter Gropius, founder of the Bauhaus movement, evaded Fascism by moving to Massachusetts, where he built this revolutionary dwelling of shimmering simplicity.

Life gets better and better. From here it is all downhill to Route 117. A sharp left takes you smoothly to an ice-cream parlour named Dairy Joy that dates from around the same era as the Gropius House. A five-dollar smoothie is all the fuel you need to survive the swerves back through the suburbs.

You soon make contact with the Charles River, alongside which you can meander downstream towards the big city. But after a taste of rural freedom, will Boston feel uncomfortably urgent? I was concerned about a passage in A Geography of Time, by the social psychologist Robert Levine. He notes that to dial the speaking clock in California, you spell out the letters P-O-P-C-O-R-N on the keypad; in Massachusetts, the code is N-E-R-V-O-U-S. Are the people of Boston jittery through too much metropolitan stress and industrial-strength coffee?

No, as it turns out. Boston is the antidote to the rest of urban America - a place with time to spare on the niceties of life. Professor Levine's investigations into the pace of life across the US hit a problem when he tried to measure walking speeds. "In many West Coast cities... we were hard-pressed to find any walkers at all." Not so in Boston, where life remains on a human scale despite the clamour of steel and glass skyscrapers.

At a downtown liquor store, where I called for a Samuel Adams (the local beer, not the independence hero), I expressed surprise that the bottle was free of state tax. "In Massachusetts," the proprietor explained, "alcohol isn't a luxury. It's a necessity."

No, it isn't - but humanity is.

TRAVELLER'S GUIDE

GETTING THERE

Simon Calder paid £402 return for a Heathrow-Boston flight on British Airways (0870 850 9 850; www.ba.com); fares this month have risen much higher. You can fly the same route on Virgin Atlantic (0870 380 2007; www.virgin-atlantic.com) and American Airlines (0845 778 9789; www.aa.com), which also flies from Manchester.

GETTING AROUND

From Logan airport, catch the free shuttle bus to Airport station, from where you can take the Blue line of the Subway (known as the "T") to the downtown stations of State or Government Center, where you can change for other destinations. The flat fare is $1.25. To travel the length of Massachusetts Avenue and to visit Lexington and Concord, rent a bicycle, for example from Boston Bike Tours (001 617 308 5902; www.bostonbiketours.com).

STAYING THERE

The writer paid $27 (£15) a night, without breakfast, at the Hostelling International summer hostels on Commonwealth Avenue (001 617 536 9455; bookable through www.hostelbookers.com, $3 fee). A good budget hotel option is the Midtown Hotel at 220 Huntington Ave (001 617 262 1000; www.midtownhotel.com) where double rooms start at $100 (£59). At the top end, the Fairmont Copley Plaza at 138 St James Avenue (001 617 267 5300; www.fairmont.com/copleyplaza) is difficult to beat. This palatial establishment has played host to every US President since it opened in 1912. A double room in July starts at $262 (£154) without breakfast.

MORE INFORMATION

Boston's main tourist office (001 617 536 4100; www.bostonusa.com) is the Boston Common Visitor Center at 147 Tremont Street, near the Park Street T stop. A second office is at the Prudential Center at 800 Boylston Street. Both open 9am-5pm daily. For more information, visit www.discovernewengland.org or call the UK representative on 01483 222676.