Martin took an active role in political and civil affairs within the proprietary's domain. He served as a vestryman for the Anglican Frederick Parish, and upon the creation of Hampshire County in 1754, he presided as the county's first justice and was further appointed the County Lieutenant. He later represented Hampshire County in the House of Burgesses from 1756 to 1758 and serving with George Washington, represented Frederick County from 1758 until 1761. Martin was appointed a trustee of the frontier towns of Winchester, Stephensburg (present-day Stephens City), and Bath (present-day Berkeley Springs). He was also appointed as the colonel of the Frederick County militia. Though not in the best of health, Martin was relied upon by the settlers of the proprietary to use his considerable resources in response to Native American attacks. Following the outbreak of the American Revolutionary War, Martin refused reappointment by Governor Patrick Henry as a justice of the Frederick County Commission of Peace. Afterward, Martin retreated from civil service entirely, and retired to Greenway Court.