John, William and Thomas Slater (Sons of James Slater)
The following, regarding John, William and Thomas Slater (the sons of James Slater), was extracted from the book, History of Washington County, Pennsylvania with Biographical Sketches of Many of Its Pioneers and Prominent Men (Boyd Crumrine, editor):
James Slater emigrated from Ireland and settled in Allegheny, where he lived and died. Three sons, John, William, and Thomas, came to this township and settled. John lives near Venice. In 1843, William and Thomas purchased ninety acres of Matthew Harbeson, and lived together ten years, the each bought farms, on which they now reside. Thomas bought one hundred and eighty-three acres of John Berry [see William Berry] in 1855. William studied for the ministry, and in 1848, soon after coming to the township, became the pastor of the Reformed Presbyterian Church near his residence, but in Chartiers township.
Crumrine, Boyd (ed.), History of Washington County, Pennsylvania with Biographical Sketches of Many of Its Pioneers and Prominent Men (Philadelphia: L. H. Everts & Company, 1882).