Cincinnati, colloquially nicknamed Cincy, is the largest city in Hamilton County, Ohio, United States, and its county seat. Settled in 1788, the city is located on the northern side of the confluence of the Licking and Ohio rivers, the latter of which marks the state line with Kentucky. The third-most populous city in Ohio with a population of 309,317 at the 2020 census, Cincinnati serves as the economic and cultural hub of the tri-state Cincinnati metropolitan area, Ohio's most populous metropolitan area and the nation's 30th-largest at over 2.3 million residents.
Throughout much of the 19th century, Cincinnati was among the top 10 U.S. cities by population. The city developed as a river town for cargo shipping by steamboats, located at the crossroads of the Northern and Southern United States, with fewer immigrants and less influence from Europe than East Coast cities in the same period. However, it received a significant number of German-speaking immigrants, who founded many of the city's cultural institutions. It later developed an industrialized economy in manufacturing. Many structures in the urban core have remained intact for 200 years; in the late 1800s, Cincinnati was commonly referred to as the "Paris of America" due mainly to ambitious architectural projects such as the Music Hall, Cincinnatian Hotel, and the Roebling Bridge.