Rev. Leason was born in Venango
Township, Butler County, PA, on April 29th, 1817, the son of Robert and Hannah (Sharp) Leason, and grandson of Robert and Hannah (Woods) Leason. Thomas Sharp Leason was the tenth in a family of
sixteen children of a farming family. He raised cattle to pay for his education at the Butler Academy, graduating from there in 1841. He attended Washington College, then Allegheny Theological Seminary
obtaining his degree m 1847. His first charge was in Marietta, Ohio; then Leechburg and Pine Run Churches, Blairsville Presbytery, locating in Brookville in 1860. After his appointment
in Jefferson County, he served the churches of Mt. Tabor at Sigel, Mt. Pleasant at Knoxdale, First Presbyterian (Pine Grove) of
Richardsville, and also a church at Mill Creek in Clarion County. His circuit covered an area of five hundred square miles. He was married in 1849, at Allegheny City, to Mrs. Mary M.
(Laird) Stewart, daughter of Rev. Francis Laird. Mary was born in Westmorland County in 1816, died in Brookville in February 1889, and is buried in the Brookville Cemetery. Rev.
Leason died in July 1891, and is buried beside his wife.