The railroad came to Bullitt County in 1851. A single track passed through Shepherdsville and Elizabethtown connecting Louisville with Nashville, Tennessee. It crossed Salt River at Shepherdsville. Between 1854 and 1858, a mail line from near Lebanon Junction to Lebanon was completed. Then in 1860 an 18 mile line was built from Bardstown Junction to Bardstown.
At the outbreak of the Civil War goods were entering Louisville from the industrial East and food was coming from the fertile Midwest. In turn these goods were shipped southward along the L&N railroad which passed through Shepherdsville and Lebanon Junction and by way of the turnpikes, one of which passed through Mount Washington.
In September, 1860, during the Civil War, Union and Confederate troops nearly met at Lebanon Junction. The Southern forces, after burning the railroad bridge over the Rolling Fork River, left before the Union troops arrived.
In September, 1862, Confederate forces occupied Shepherdsville and destroyed the railroad bridge over the Salt River. Shepherdsville was retaken by Union forces led by Buell and the L&N built a new bridge.
In October, 1862, the locally famous battle at Perryville, Kentucky took place. Confederate troops that had been camped near Bardstown were slowly retreating southward while Union soldiers, commanded by Major General Don Carlos Buell, were leaving Louisville in pursuit.
Because of the scarcity of water, Buell sent one of his three corps by way of Taylorsville, one by way of Mount Washington, and the third by way of Shepherdsville. Coming together at Perryville the two armies fought the bloodiest battle ever fought in Kentucky.
During the Civil War, merchants in Louisville continued to carry on a brisk trade with the southern states. When the Union forces put a stop to this by checking goods leaving the Louisville station for points southward, the merchants simply sent their goods by wagon to Shepherdsville where they could be loaded on the trains.
Like most parts of Kentucky, Bullitt County sent young men to serve in both the Union and the Confederate forces. Many of them distinguished themselves during the war.