The Willian Silliman you mention was the son of John and Christina (Barrett) Silliman and was born at Urbana, Steuben Co. NY about 1852. He married Hannah, dau of John and Hannah (Chilson) Beam, born at Mitchellsville, Steuben Co. NY about 1856.
John Silliman was born in Steuben Co. NY about 1818 and died at Urbana, Steuben Co. NY, 1 Nov 1891. He married after 1849, 3rd wife Christina, dau. of Ebenezer and Rachel (Westervelt) Barrett.
John Sillman's parents were Thomas and Mary E. (Kinney) Sillyman. Thomas was born in PA or NY about 1794 and died in Steuben Co. NY, 28 August 1858, Mary was born in PA about 1799.