The River City. Marietta, in Ohio was one of the earliest premanent settlements in the US and as the new frontier, building steamboats and home to riverboats, has a long and vibrant history. Marietta, known as the River City, was the first permanent settlement of the Northwest Territory. In 1788, General Rufus Putnam and 48 pioneers founded this organized settlement at the confluence of the Ohio and Muskingum Rivers, eventually...