Washington Township was one of the original townships of Clermont County. In its first term, on February 25, 1801, the Justices' Court of General Quarter Sessions divided the new Clermont County into five townships. One of these was Washington Township.
The original Washington Township was greatly diminished by the later formation of Franklin and Monroe Townships from parts of the original Washington Township.
The land area of Washington Township is generally hilly from the river hills, and from its principal streams, Bear Creek, Maple Creek and the larger Big Indian Creek, with its North Fork Branch and Stony Fork Branch.
Washington Township is bounded on the west by Monroe Township, on the north by Tate Township, on the east by Franklin Township, and on the south by the Ohio River. It has two sizeable river towns, Moscow, and Neville, within its boundaries. These river towns were important locations in the days of the steamboats.
Washington Township has the distinction of being the location of the first survey made in the Northwest Territory. This survey was made by John O'Bannon, the pioneer deputy surveyor, on November 13, 1787, and includes the town of Neville. He made the survey for Colonel John Neville, who was an Officer of the Revolutionary War in the Virginia Line. The Survey number 388, was for 1400 acres, established on military warrant number 937. The chain-carriers were John Williams, Sylvester Montroney, and James Blair. The survey is said to have been so accurately executed that its lines and boundaries were never disputed as were many other early surveys with the county. (Clermont County, Ohio 1891 Atlas & History Millennium Reprint)
There are many historical sites such as Edgington Mound, and many other historical sites scattered through the township.