<P> Between 9 and 10 pm on the night of April 18, 1775, Joseph Warren told Revere and William Dawes that the British troops were about to embark in boats from Boston bound for Cambridge and the road to Lexington and Concord . Warren's intelligence suggested that the most likely objectives of the regulars' movements later that night would be the capture of Adams and Hancock . They did not worry about the possibility of regulars marching to Concord, since the supplies at Concord were safe, but they did think their leaders in Lexington were unaware of the potential danger that night . Revere and Dawes were sent out to warn them and to alert colonial militias in nearby towns . </P> <P> Dawes covered the southern land route by horseback across Boston Neck and over the Great Bridge to Lexington . Revere first gave instructions to send a signal to Charlestown using lanterns hung in the steeple of Boston's Old North Church . He then traveled the northern water route, crossing the mouth of the Charles River by rowboat, slipping past the British warship HMS Somerset at anchor . Crossings were banned at that hour, but Revere safely landed in Charlestown and rode west to Lexington, warning almost every house along the route . Additional riders were sent north from Charlestown . </P> <P> After they arrived in Lexington, Revere, Dawes, Hancock, and Adams discussed the situation with the militia assembling there . They believed that the forces leaving the city were too large for the sole task of arresting two men and that Concord was the main target . The Lexington men dispatched riders to the surrounding towns, and Revere and Dawes continued along the road to Concord accompanied by Samuel Prescott . In Lincoln, they ran into the British patrol led by Major Mitchell . Revere was captured, Dawes was thrown from his horse, and only Prescott escaped to reach Concord . Additional riders were sent out from Concord . </P> <P> The ride of Revere, Dawes, and Prescott triggered a flexible system of "alarm and muster" that had been carefully developed months before, in reaction to the colonists' impotent response to the Powder Alarm . This system was an improved version of an old notification network for use in times of emergency . The colonists had periodically used it during the early years of Indian wars in the colony, before it fell into disuse in the French and Indian War . In addition to other express riders delivering messages, bells, drums, alarm guns, bonfires and a trumpet were used for rapid communication from town to town, notifying the rebels in dozens of eastern Massachusetts villages that they should muster their militias because over 500 regulars were leaving Boston . This system was so effective that people in towns 25 miles (40 km) from Boston were aware of the army's movements while they were still unloading boats in Cambridge . These early warnings played a crucial role in assembling a sufficient number of colonial militia to inflict heavy damage on the British regulars later in the day . Adams and Hancock were eventually moved to safety, first to what is now Burlington and later to Billerica . </P>

What was the importance of lexington and concord to the american revolution