Trail of the unexpected: The Grand Old Ditch

Lives, fortunes and hopes: all were squandered during the tortuous construction of America's finest bike path. That might sound absurd – but the real folly is the Chesapeake and Ohio Canal, a waterway that swerves gracefully through the modest, misshapen state of Maryland, and whose towpath provides an ideal cycle-trip. In three days you can ride through benign woodland and rolling hills, with diversions to locations crucial to the history of America, and end in the nation's capital.

The C&O, as the canal is affectionately known, redefines the term "doomed to failure". The first president of the United States shoulders much of the blame: Washington dreamed of a waterway connecting the Atlantic with the west of the young nation. The path he chose was a link between Chesapeake Bay and the headwaters of the Ohio River. There was even a ready-made valley for much of the route, in the shape of the shallow and largely unnavigable Potomac River. So George Washington founded the Patowmack Company to create such a grand, unifying canal.

When the father of America passed away in the dying days of the 18th Century, the idea might have perished. But investors whose cash reserves exceeded their sense persevered with the plan. The first spade of earth was turned at Little Falls, Maryland on Independence Day 1828 – which turned out to be a crucial day in opening up America, but not because of the C&O Canal. On the same day, further east in the state, work began on the Baltimore and Ohio Railroad. Railways would, ultimately, unite the states.

After 22 years, the canal reached the town of Cumberland, Maryland. The railway had got here eight years earlier. West of Cumberland, the terrain rises steeply, ensuring the "O" in C&O would remain unattainable.

Today, the town provides the starting gate for hikers and bikers on the 185-mile towpath to the capital. It typifies small-town America; the most fun you can find on a Saturday night is in the Republican Club. On a Sunday morning, you can start crunching your way east along the clay-and-crushed-stone towpath – nudged by a breeze from the west and with the pleasing notion that, during the course of the ride, you will descend 605ft.

The engineering marvels begin almost at once, in the shape of the Evitts Creek Aqueduct, which carries the canal high above one of the tributaries of the Potomac. The C&O shadows the northern bank of the Potomac for its entire length, providing a wide, shallow and meandering companion. Soon, you encounter the first three of the 74 locks; elaborate masonry eased the descent of the coal barges that, sporadically at least, exploited the C&O. The locks, like almost all of the canal, are now empty. So is the Paw Paw Tunnel, a 3,100-foot short-cut.

Like the canal that traces its southern frontier, Maryland is a state in the shadows – partly because of its unfortunate shape. At the quiet town of Hancock, a comfortable day's cycle from Cumberland, the state is squeezed between West Virginia and Pennsylvania to just a couple of miles wide. And, downstream, a chunk of Maryland was excised to help create the ragged diamond of the District of Columbia. The state's only real city, Baltimore, remains constantly in the shadows of Washington and Philadelphia. It is the ninth-smallest in the union.

Federal funds have financed the revival of the C&O as a National Historic Park, with interpretive panels and visitor centres scattered along its length. Only a completist, though, would stick doggedly to the towpath: spinning off at Horseshoe Bend, you can visit the sombre Civil War battlefield of Antietam. At the confluence of the Shenandoah River, the West Virginia town of Harpers Ferry was one of the flashpoints for the conflict; the abolitionist John Brown led a raid on the town's arsenal, for which he was hanged.

East from here, Virginia becomes the neighbouring state. Gradually the landscape softens, and becomes more populated.

After ducking under the Beltway – Washington DC's version of the M25 – the canal has one trick left. The final lock is known as the Watergate, and gave its name to an office block that overlooks it. This was the headquarters for the 1972 Democratic Party campaign, whose offices were burgled on the orders of the Nixon White House. Presidents come and presidents go, but the "Grand Old Ditch" rolls on forever.

C&O Canal National Historical Park: 00 1 301 739 4200; www.nps.gov/choh

State Lines: Maryland

Population 5.2 million
Area 1.5 times size of Wales
Capital Annapolis
Date in Union 28 April, 1788
Flower Black-eyed Susan
Motto "Strong deeds, gentle words"
Nickname The Old Line State

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