CONCORD, Mass. -- Colonial minutemen drove British redcoats from the Old North Bridge on Saturday -- just as they did 225 years ago when the "shot heard round the world" opened the Revolutionary War.

Thousands of war re-enactors from across the United States, Canada and England gathered in Lexington and Concord, Mass., and as many as 200,000 spectators were expected to watch the weekend re-enactments, including Paul Revere's ride and the legendary battle at the bridge in Concord.At dawn Saturday, mock gunfire sounded across the village green at Lexington, now hemmed in by houses that didn't exist 225 years ago.

On April 18, 1775, British soldiers were sent to destroy the colonials' supply depot at Concord.

Revere and William Dawes sounded the alarm, and at dawn on April 19, 1775, the two sides faced each other on the Lexington green. Eight colonists were killed.

The British marched on to Concord where they destroyed the military supplies and exchanged fire with more minutemen.

Then, retreating to Boston, the redcoats were fired upon by colonials along what is now called the Battle Road. The British suffered 273 casualties, including 99 dead or missing; the Colonists suffered 95 casualties, including 54 dead or missing.