He was born in Franklin County, New York, to Samuel Smith Clark (1801–1870) and Jane Ann (Wead) Clark (1806–1872) on May 27, 1829. Samuel Smith Clark was Franklin County Clerk from 1832 to 1834. Samuel's father was Benjamin Clark who was First Judge of the Franklin County Court from 1825 to 1829. In 1851, Benjamin S. W. Clark married Adaline W. Meigs.
^"Warden of Sing Sing". The New York Times. February 9, 1878. Retrieved 2011-04-18. ... in the place of Benjamin S. W. Clark, appointed Superintendent of Public Works ... to Superintendent Pilsbury as the proper person to succeed Mr. Clark. ...
^"Clark's Nomination Confirmed". The New York Times. January 31, 1878. Retrieved 2011-05-03. The nomination of Benjamin S.W. Clark, as Superintendent of Public Works, was confirmed in Executive Session of the Senate today by a unanimous vote. ...