It is often underappreciated how the Louisville & Nashville Railroad’s status impacted the operations of Major General W.S. Rosecrans and the Army of the Cumberland. I discuss it in this except from my book about Stones River and Tullahoma:
Throughout the war, of the three major Federal armies (the Army of the Potomac, Army of the Cumberland, and the Army of the Tennessee), the Army of the Cumberland consistently had the longest and most vulnerable supply lines. Rosecrans’ main logistical base was at Louisville, 183 miles north of his forward depot at Nashville. Two viable supply routes connected the cities: via ship along the Ohio and Cumberland Rivers, or along the Louisville & Nashville (L&N) Railroad. Low water levels at the Harpeth Shoals, 20 miles downstream of Nashville, limited river traffic that fall to all but the shallowest-draft ships, forcing Rosecrans’ lifeline to ride the rails of the L&N.
The L&N ran south from Louisville up Muldraugh Hill (site of present day Fort Knox) then through Elizabethtown and south to the Green River crossing at Munfordville, site of the siege and surrender in September 1862. It then headed south to Bowling Green and then southeast into Tennessee, entering the state at Mitchellsville. From there the railroad ran through an 800-foot-long tunnel north of Gallatin. After passing the rail yards at Gallatin, it turned southwest and entered Nashville from the north, where it linked with the Nashville & Chattanooga Railroad to service traffic headed southeast. Almost every one of its 183 miles passed through neutral or hostile territory, making the L&N highly vulnerable to raids by Confederate cavalry or guerrillas. Colonel Morgan’s cavalry had done serious damage to the line, even burning the Gallatin Tunnel in August. The L&N’s tracks were operational to Mitchellsville in the middle of November, which necessitated a long and slow wagon trip over the 40 miles from that point to Nashville. The railroad reopened all the way to the state capital on November 25; the arrival of a train from Louisville made the front page of the Nashville newspapers. In the 365-day period from July 1, 1862 to June 30, 1863, the railroad was completely functional only 7 months and 12 days. Each closing of the L&N slowed or halted Rosecrans’ supply buildup and operations.