County was the first county settled in the old Northwest Territory.
Marietta, Ohio, was settled on 7 April 1788 by the Ohio Company
of Associates, a group of Revolutionary War officers who were paid for
their services in land. Like many other places in the United
States, it was named for George Washington, and yes, Washington had
first-hand knowledge of this area. His survey party camped at
present-day Reno, Ohio, on 26 October 1770.
His opinion of the new settlement in June 1788 was glowing:
colony in America was ever settled under such favorable auspices as
that which has just commenced at the Muskingum. If I was a young
man, just preparing to begin the world, or if advanced in life
and had a family to make provision for, I know of no country where I
should rather fix my habitation."
Washington County was one of the the original counties in the state of
Ohio and the first to organize. Marietta,
Ohio, was named by the Revolutionary War veterans after Marie
Antoinette for her contributions in the American Revolution.
Marietta, Ohio, was a planned community, with the streets and lots
drawn up before the Ohio Company land was sold.
earthworks (mounds) have existed in the county since the Hopewell and
Adena cultures, as described by Squier and Davis.
Marietta Earthworks, by Charles Whittlesey, in Squier & Davis,
Ancient Monuments of the Mississippi Valley
Early fortifications were the pentagonal-shaped Fort Harmar (1785), on the west side of the Muskingum River
Martius" on the east side of the Muskingum River,
and the "Picketed Point" at the confluence of the Ohio and Muskingum Rivers in Marietta,
Fort Frye up the Muskingum River,
and Farmers' Castle in Belpre.