Tunnel Hill was incorporated in 1848, and in 1849 Georgia began building a depot there in anticipation of the Western and Atlantic Railroad, which linked Atlanta and Chattanooga. Before the line could be completed, a tunnel had to be cut through nearby Chetoogeta Mountain, and using slave labor this work was finished in October 1849; the first train arrived on May 9, 1850. The depot still stands nearby, the old tunnel became a tourist attraction, and the home built by Mr. Clisby Austin at about the same time, known as the Clisby Austin House or Meadowlawn, is also visible. Tunnel Hill saw several Civil War events, including the Great Locomotive Chase, or Andrews Raid, on April 12, 1862, when the stolen locomotive General and the pursuing locomotive Texas passed through the tunnel and town before the chase ended north of Ringgold with the capture of the General. On September 11, 1863, during the Federal army's movement into Georgia before the battle of Chickamauga, Union Colonel John T. Wilder's Lightning Brigade of mounted infantry met Confederate cavalry south of Ringgold; the Southern troopers withdrew fighting toward Tunnel Hill, Brigadier General Nathan Bedford Forrest was slightly wounded, and the Federals returned to Ringgold at dark. After the Confederate defeat near Chattanooga in November 1863, Tunnel Hill lay between Confederates at Dalton and Federals at Ringgold. On February 23, 1864, elements of two Federal corps advanced on Confederate cavalry holding an advanced position at Tunnel Hill and then quickly retired; the feint alarmed General Joseph E. Johnston enough that he canceled an order sending part of his army to oppose Union Major General William T. Sherman's Meridian, Mississippi, campaign. On May 7, 1864, as Union Major General John M. Palmer's 14th Corps advanced on Tunnel Hill, the first shots of Sherman's Atlanta Campaign were fired from a Federal battery on a hill near the Clisby Austin House; the battery and supporting infantry drove Confederate cavalry from town and helped open the way for Federal armies to move against Johnston at Dalton. Sherman arrived in Tunnel Hill late that day and used the Clisby Austin House as his headquarters until leaving on May 12 to join the Federal Army of the Tennessee near Resaca. The last skirmish at Tunnel Hill came on March 3, 1865, when Confederate cavalry led by Major General Joseph Wheeler attacked a squad of Federal soldiers from the 145th Indiana Infantry.