In early July 1863, as the Confederate Army of Tennessee occupied Chattanooga and expected the pursuing Federal Army of the Cumberland to cross the Tennessee River above the city, cut off Confederate forces at Knoxville, and attack from the north, security for the railroad became a primary concern. After east Tennessee Unionists burned two railroad bridges in the Tyner area, General Patrick R. Cleburne, an Irish-born division commander, was sent to guard the area. To protect the railroads at Tyner and defend the approaches to Chattanooga, he immediately began constructing four large earthwork redoubts, or forts, in and near Tyner's Station. Their walls stood twelve feet high and measured 200 to 300 feet in diameter, with embrasures for cannon, openings for rifles, and surrounding rifle pits. Cleburne made his headquarters near one of the main forts at Tyner, and one soldier later recalled that while encamped there the troops were kept busy drilling and constructing forts and earthworks. Built of earth by hand labor with picks, shovels, and wheelbarrows, the first fort stood a short distance south of the house used as Cleburne's headquarters and about 2000 feet north of the railroad, near the unfinished railroad from Tyner to Harrison; the second stood about 2000 feet south of the railroad; the third was about 2000 feet north of the intersection of the modern U.S. highways 11 and 153; and the fourth was on a hill about 2000 feet south of that intersection. Federal forces clearly recognized Tyner's Station's importance: after the Confederate withdrawal to Georgia in September 1863, the 123rd Illinois Mounted Infantry Regiment, with Wilder's Brigade of Mounted Infantry that included the 17th Indiana and 92nd Illinois and Lilly's 18th Indiana battery, crossed the Tennessee River on September 10 and captured a large rebel mail at Tyner's Station, while other sources indicate Union troops also burned two caissons there. After the Battle of Missionary Ridge, the fort at Tyner was occupied by the Federal Army for the rest of the war. Colonel Horace Boughton of the 143rd New York Infantry, commanding a brigade that included that unit, was in command at Cleveland with responsibility for guarding the East Tennessee and Georgia Railroad from Chattanooga to Cleveland, and on December 3, 1864, he reported that he had 200 men and two pieces of artillery behind a good earthwork at Tyner's Station. In October 1864, Colonel Lewis Johnson, a German-born Federal officer, was ordered to the fort at Tyner with the 44th US Colored Infantry Regiment, a noted U.S.C.T. unit that had been captured by the Confederates at Dalton, Georgia, and while at Tyner he reorganized the regiment and brought it up to strength through recruitment.