Born in Hansonville (now Russell County), Virginia, Estil received an academic education, and attended Washington Academy (now Washington and Lee University), Lexington, Virginia. He studied law. He was admitted to the bar and commenced practice in Abingdon, Virginia. He served as prosecuting attorney for Washington County. He served as member of the Virginia House of Delegates during the years 1814–1817.
Estil was elected as an Adams candidate to the Nineteenth Congress (March 4, 1825 – March 3, 1827). He served as judge of the fifteenth judicial circuit from 1831 until 1852, when he resigned. He retired to a farm in Oldham County, Kentucky, where he died July 14, 1853.