Louisville and Nashville Railroad

Its first line extended barely south of Louisville, Kentucky, and it took until 1859 to span the 180-odd miles (290 km) to its second namesake city of Nashville. There were about 250 miles (400 km) of track in the system by the outbreak of the Civil War, and its strategic location, spanning the Union and Confederate lines, made it of great interest to both governments.

During the Civil War, different parts of the network were pressed into service by both armies at various times, and considerable damage from wear, battle, and sabotage occurred. For example, during the Battle of Lebanon in July 1863, the company's depot in Lebanon, Kentucky, was used as a stronghold by outnumbered Union troops.

However, the company benefited from being based in Kentucky, a southern border state that initially had competing Unionist and Confederate state governments, but with Bowling Green (the latter's capital) and Nashville falling to Union forces within the first year of the war, remaining in their hands for the war's duration. The company profited from Northern haulage contracts for troops and supplies, paid in sound Federal greenbacks, as opposed to the rapidly depreciating Confederate dollars.

The Humming Bird and Pan-American, both from Cincinnati to New Orleans and Memphis, were two of the L&N's most popular passenger trains that ran entirely on its own lines. However, the Humming Bird later added a Chicago to New Orleans section in conjunction with the Chicago & Eastern Illinois Railroad utilizing the Georgian north of Nashville. (The Official Guide of the Railroads, February 1952) The railroad also hosted other named trains, including:

Azalean (Cincinnati – New Orleans) (had through Pullman Company Sleeping Cars between Cincinnati and New York over the Pennsylvania Railroad) ran combined with the Washington – Atlanta – New Orleans Express (New York – New Orleans in conjunction with the Pennsylvania Railroad, Southern Railway and the West Point Route); these trains combined south of Montgomery.

Pre-Amtrak Crescent (New York – New Orleans in conjunction with the Pennsylvania Railroad, Southern Railway and the West Point Route)

Dixie Flagler (Chicago – Miami in conjunction with the Chicago & Eastern Illinois Railroad, Nashville, Chattanooga and St. Louis Railway, Atlantic Coast Line Railroad and the Florida East Coast Railway)