The Prescott Guards, also known as the Pepperell Light Infantry Company, were an independent, volunteer militia company, organized in 1819 in Pepperell, Massachusetts. They were named after Colonel William Prescott, who is known for his service in the Revolutionary War, specifically at the Battle of Bunker Hill. The Prescott Guards replaced the South Company, an infantry company under the command of Captain David Shed that had previously disbanded in the Pepperell area. Membership in the Prescott Guards and the nearby North Company was determined by the territory in which the individual claimed residence. Company musters were held six times a year, usually on the Pepperell Common or in neighboring towns of Groton, Littleton, Townsend, or Chelmsford.

From 1840 through 1854, the Prescott Guards constituted Company B, 5th Regiment, 3rd Brigade, 2nd Division of the Massachusetts Volunteer Militia. In 1855, it became Company A, 6th Regiment, 3rd Brigade, 2nd Division of the Massachusetts Volunteer Militia. In 1857, the company numbers fell below the minimum required by law and the company was disbanded. In 1861 an attempt was made to reorganize the company, but without success. At the beginning of the Civil War, many of the Prescott Guards’ former members served with the 6th Regiment of the Massachusetts Volunteer Militia.