On April 18th, 1775, the King's Own and other British Regulars were woken in the early evening. The goal: march from Boston to Concord, Massachusetts, to find and destroy stores and ammunition that seditious locals were stockpiling. After marching down to the back bay of Boston, some 800 men were ferried to Cambridge and, around 1AM on April 19th, they started their long march towards Concord.

Along the way, the Regulars heard town bells ringing and musket shots firing. The officers also noticed, at times, that the army was being shadowed. The countryside was being alerted to their presence, and British apprehension rose quickly. For several years, the inhabitants of Boston had abused the soldiers, seizing any opportunity to make them feel unwelcome. The Regulars had been forced to stifle their anger and hatred, but it simmered under the surface nonetheless.

Shortly after 5AM, the Regulars reached the farm town of Lexington and saw, on the common, some 70 militia armed and assembled; more were entering the meeting-house to gather arms. Angered by this open defiance, Major Pitcairn ordered a group of Regulars to cut off access to the house. Two other companies of Regulars stormed quickly from marching columns into fighting position opposite the militia. The King's Own was one of these companies.

"Lay down your arms, you damned rebels," yelled the British Officer. And it is believed that the militia were about to break, for they were vastly outnumbered and a strong opposition had been made. But there was a firing of a musket; by whom, no one knows. Releasing years of frustration and anger, the Regulars fired into the militia and pursued them off the Green.

With great difficulty, the British Officers returned the Regulars to order. But order was not achieved before 8 militia were killed. The American Revolution had truly begun.

The King's Own and other Regulars were ordered back into columns and they marched on towards Concord to complete their mission. There, the King's Own would enter an engagement at the Old North Bridge.