Prehistoric cultural affiliation(s) include Adena and Hopewell dating back to 499 BC.
Several famous people are associated with these Washington County historic places including Col. Josiah Harmar, Rufus Putnam, Thomas H. Cisler and Gen. Rufus Putnam.
Some of the country's most noteable architects helped create the Washington County places including Adolph "Delph" Morris, John M. Slocomb and George W. Hovey. Prominent architectural styles found in Washington Country are Greek Revival, Federal and Late Victorian.