The trigger guard is of Dutch form but is probably American-made. The butt-plate tang is of the stepped design favored in British military and hunting guns.
Despite service during the French and Indian War, Parker, a farmer and mechanic in rural Lexington, would most likely not have owned a traditional military firearm, but rather one more suitable for hunting such as this fowling piece. It is not known if Parker, as the captain of the Lexington Minutemen, actually fired this weapon on that historic morning, but his musket is one of the rare documented artifacts of the day.
Parker died less than six months after the Battle at Lexington, his firearm and other personal effects descending to his children. Despite its uniqueness among extant artifacts, firearms were expensive and continued to be used long after the Revolution, evidenced by extensive burn-back, as well as modernization or replacement of many parts, probably during the 1820s.