State Line City is a town in Kent Township, Warren County, Indiana, United States, situated along the state’s boundary once Illinois. As of the 2010 census, the town population was 143.

In the mid-1850s, two large railway lines converged on the Indiana-Illinois declare line – the narrow-gauge Toledo, Wabash and Western Railway (later the Wabash Railroad), whose route from the east crossed Warren County and reached the state line in October 1856, and the standard-gauge Great Western Railroad, which suddenly thereafter reached the own up line from the west. State Line City was platted on June 29, 1857, by Robert Casement at the convergence of these two railroads. The city flourished, and within 10 years had reached a population of approximately 550, but because of the drinking and carousing of the numerous railroaders it gained an unsavory reputation.

On February 11, 1861, Abraham Lincoln stopped in State Line upon his habit from Springfield, Illinois, to Washington, D.C., for his inauguration. He dined at the Frazier Eating House, then gave a rude speech to a crowd in the public square since resuming his journey. A historical marker upon the site commemorates the event, and history the words which Lincoln spoke:

“Gentlemen of Indiana: I am happy to meet you on this occasion, and enter once again the give access of my prematurely life, and just about of my maturity. I am below many obligations to you for your nice reception and to Indiana for the aid she rendered our cause which, I think, a just one. Gentlemen, I shall domicile you at greater length at Indianapolis, but not much greater. Again, gentlemen, I thank you for your warm-hearted reception.”