Cincinnati -- the county seat of Hamilton County -- began as Losantiville and Fort Washington. The settlement began on the north side of the Ohio River, about midway between two northern tributaries, the Great and Little Miami rivers, and opposite a southern tributary, the Licking River in Kentucky (then still part of Virginia). The first three settlements were along the Ohio River -- Columbia, near the mouth of the Little Miami; Losantiville, opposite the Licking; and North Bend, west of the mouth of the Great Miami River. An Ohio Historical Society web site says: "In 1788, Israel Ludlow, Matthias Denman, and Robert Patterson purchased 800 acres from John Cleves Symmes along the Ohio River at the Licking River's mouth. Symmes had purchased two million acres of land from the Confederation Congress in 1787 and now hoped to become rich by selling parts of the Symmes Purchase [Miami Purchase] to others. Denman provided the necessary cash; Patterson found settlers; and Ludlow surveyed the land to make sales and also established a town. By early January 1789, Ludlow had plotted the town, dividing it into two types of lots. Near the town's center, lots were one-half acre, and outlying lots were four acres. Ludlow, Denman, and Patterson provided the first 30 settlers with two free lots, one of each type. The three men named the town Losantiville.
The town grew slowly. One month after the settlement was established, only three log cabins existed in Losantiville. On the outlying lots, settlers had constructed twenty cabins and one frame house. Eleven families and two dozen single men lived on the land. In August 1789, the village began to grow quickly. In that month, Josiah Harmar authorized the construction of Fort Washington to protect settlers in both the Symmes Purchase and the Miami Purchase, as well as in northern Kentucky. The fort was located just west of Denman's, Ludlow's, and Patterson's 800 acres of land. When completed in December 1789, Harmar made Fort Washington his headquarters. Usually 300 soldiers lived in the fort, increasing Losantiville's population to nearly five hundred people."
In 1790, Gov. Arthur St. Clair established Hamilton County and made Losantiville the county seat. "St. Clair disliked the name Losantiville and changed the town's name to Cincinnati. An additional 250 families arrived later that year, swelling the town's population to nearly 700 people." The OHS account continues: "During 1790 and 1791, thousands of militiamen from Kentucky and Pennsylvania flooded Cincinnati as Harmar and eventually St. Clair planned expeditions against the Native Americans. St. Clair faced such a difficult time maintaining control of his men in the town, with three taverns, that he moved his men to nearby Ludlow's Station. After St. Clair's defeat, occurring at the hands of the Indians in 1791, many settlers fled Cincinnati, fearing that the natives would descend upon them. Despite the lack of order and the various safety concerns, hundreds of settlers flooded the town. They believed that they could make their fortunes providing the soldiers and people traveling down the Ohio River with supplies. By the summer of 1792, 30 warehouses existed in Cincinnati to meet the needs of these two groups of people.
With the success of Anthony Wayne against the Indians at the Battle of Fallen Timbers in 1794, hundreds of settlers flocked to the community, including a French pastry chef and a hairdresser. By early 1795, a spinning wheel manufacturer, a brewer, a chair manufacturer, and a butcher all had opened up businesses. By 1803, the year that the United States Army abandoned Fort Washington, the city had roughly one thousand civilians. It continued to grow, reaching nearly 10,000 residents by 1820. Cincinnati had emerged as a major city, primarily due to its strategic location on the Ohio River." (See Northwest Territory, Miami Purchase, Hamilton County, Fort Washington, Fort Hamilton, Harmar's defeat, St. Clair's defeat, Fort Recovery, Kekionga, Fallen Timbers and Treaty of Greenville.)