What started the fighting at Lexington and Concord?

General Gage, commander of British troops in Boston, had for some time been engaging in forays to capture stores of guns and ammunition held by the colonists. He had sent troops to Plymouth, Portsmouth NH, and Salem on such missions, all failed. But those missions had been carried out by small numbers of troops.

In April 1775 American spies in the British camp discovered Gage's plan to send a large number of troops, 900 in all as it turned out, to capture the arms and gun powder stored at Concord.

In the very early morning hours he sent 500 of his troops across the Charles River to Cambridge to begin their march to Lexington first, about 12 miles, and then to Concord. He sent his artillery, another 400 troops, south by land through Dorchester and Watertown with the intention of meeting up at Lexington.

Paul Revere and Charles Dawes, via separate routes, set out to warn John Hancock who was in a tavern in Lexington of the British actions. Neither actually made it but a third rider, Dr. Prescott who had joined them en route did get to Lexington.

Each town in Massachusetts had a committee in place for the defense of its town and during his ride Revere and others warned members of those committees of the British actions who in turned sent out the alarm to form each town's militia and head to Lexington.

The scuffle in Lexington was very brief and saw the colonies make a very hasty retreat. But as Gage's troops approached Concord he started taking on fire as various militia groups arrived. The British troops were turned back at Concord and suffered almost continual attack on its retreat to Boston.

Hancock, John and Samuel Adams, and others had known such resistance meant war even before April 19th but felt the crown had eroded to many of their rights and were finally prepared to fight for them. The right of bear arms was prime to them.