MARIETTA, a city of south-eastern Ohio, U.S.A., the county seat of Washington county; on the Ohio river at the mouth of the Muskingum. It is on Federal highways 21 and 5o, and is served by the Baltimore and Ohio and the Pennsylvania railways. Pop. 15,14o in 1920 (95% native white); and 14,285 in 193o by Federal census. The city's streets are lined with magnificent old shade trees, including the largest elm on record in the United States. It is surrounded by a hilly country of much natural beauty, devoted largely to market gardens and apple orchards; is the centre of one of the oldest gas and oil fields in the country, still producing about 1,250,000 bbl. annually ; and has substantial and diversified manufacturing industries, with an output in 1927 valued at $12,213,00o. The assessed valuation of property for 1927 was The city operates under the mayor-and council form of government, and has in addition a "service direc tor" with the functions of a city manager. It is the seat of Marietta college (chartered 1835, continuing an academy founded in 1797) which has a valuable historical museum and rare col lections of Americana, including the original records of the Ohio Company, the Rodney M. Stimson collection (relating chiefly
to the history of the Ohio and the Mississippi valleys), and the Charles Goddard Slack collection of historical documents and prints. In the centre of Mound cemetery (where many of the pioneers are buried) is one of the most perfect specimens of the mound-builders' work, and there are other prehistoric earthworks in and near the city, including a double embankment leading down to the Muskingum river. Marietta is the oldest settlement in Ohio. It was founded on April 7, 1788 (near Ft. Harmer, built in 1785) by a company of revolutionary officers from New Eng land under the leadership of Gen. Rufus Putnam. The name was chosen to honour Marie Antoinette. Here the North-west territory was formally organized, Marietta was made the capital, and on July i 5 Arthur St. Clair took his oath of office as the first governor. The blockhouse ("Campus Martius") in which Gen. Putnam lived at first, his later home, and the original land office of the Ohio Company, still stand, and are carefully preserved as historic monuments. Black Hole cave, in the outskirts of the city, was an important "station" on the Underground railway.