The Lexington militia did not intend to fight the British Regulars

As a show of force to let the British government know that the colonists were armed and prepared to defend themselves, the Lexington militiamen marched onto Lexington Green on the morning of April 19, 1775.

The Lexington militia had no desire to engage the British Regulars in a firefight, just like previous militia groups had followed other Regular incursions (most notably at Salem, Massachusetts on February 26, 1775). That morning, Captain John Parker showed himself to be a stable commander of the militia because he understood that sending his 80 men up against the 400 skilled British Regulars would be suicide.

Parker didn't want to obstruct their path to Concord, as evidenced by the positioning of his soldiers off to the side of the road. Post-war versions of Parker's statements from that morning have been embellished, but his deeds and the firsthand testimonies of those who were there demonstrate that Parker had no desire to engage in combat.