Chattanooga is a city in and the county seat of Hamilton County, Tennessee, along the Tennessee River bordering Georgia. The city also extends into Marion County on its western end. With a population of 181,099 in 2020, it is Tennessee's fourth-largest city and one of the two principal cities of East Tennessee, along with Knoxville. The city anchors the Chattanooga metropolitan area, Tennessee's fourth-largest metropolitan statistical area, as well as a larger three-state area that includes Southeast Tennessee, Northwest Georgia, and Northeast Alabama. Served by multiple railroads and Interstate highways, Chattanooga is a transit hub. It is 118 miles (190 km) northwest of Atlanta, Georgia, 112 miles (180 km) southwest of Knoxville, Tennessee, 134 miles (216 km) southeast of Nashville, Tennessee, 102 miles (164 km) east-northeast of Huntsville, Alabama, and 147 miles (237 km) northeast of Birmingham, Alabama.
Chattanooga was a crucial city during the American Civil War, due to the multiple railroads that converge there. After the war, the railroads allowed for the city to grow into one of the Southeastern United States' largest heavy industrial hubs. Today, major industry that drives the economy includes automotive, advanced manufacturing, food and beverage production, healthcare, insurance, tourism, and back office and corporate headquarters.With a downtown elevation of about 680 feet (210 m), Chattanooga is at the transition between the ridge-and-valley portion of the Appalachian Mountains and the Cumberland Plateau. Its official nickname is "Scenic City", alluding to the surrounding by mountains and ridges. Unofficial nicknames include "River City", "Chatt", "Nooga", "Chattown", and "Gig City", the latter a reference to Chattanooga's claims that it has the fastest internet service in the Western Hemisphere.Chattanooga is internationally known for the 1941 hit song "Chattanooga Choo Choo" by Glenn Miller and his orchestra. It is home to the University of Tennessee at Chattanooga (UTC) and Chattanooga State Community College.