 When the war ended in 1763, Miller settled at Staunton, Virginia, and practiced medicine.Although a Presbyterian rather than a member of the Church of England, he was elected to the Augusta parish vestry in 1764, indicating his rising social status after his marriage, as well as his community involvement (the vestry being responsible for providing social services in the county).In May 1765, his social position had increased further and he was elected to his first political office, as justice of the peace, on the same day as he increased his real estate holdings by purchasing 560 acres from William Beverley.