It began in Porter and was extended south through Dover andSeaford before reaching Delmar on the border of Maryland in 1859.

The railroad was conceived in 1836 by John M. Clayton, a former United States senator who obtained a charter from the Delaware General Assembly to serve the Delmarva Peninsula.

He was concerned that a proposal in Maryland to build a line along the western side of the peninsula would harm Delaware's economy.

Delaware was highly motivated and exempted the railroad from taxation for fifty years and provided other incentives.

It called for a line from Dona Landing (just east of Dover) to Seaford that would be part of a Philadelphia to Norfolk route.

[5] Sufficient investment was secured by 1852, when the state of Delaware stepped in and bought 5,000 shares of stock to its construction allowing commencement of the operation.

Moving the northern terminus from Dona Landing to Porter added approximately 35 miles (56 km) to the originally planned length.

Railroad access spurred the growth of farms in this part of the state as farmers had means to ship produce north to Philadelphia, New York and Boston.

After completing its line to Delmar, the Delaware Railroad starting building branches and acquiring control of those that connected to it in Delmarva.

Prior to the Civil War, southern sympathizers utilized the railroad as a route south to join the Confederacy.

du Pont) advised General Robert E. Lee that the railroad should be destroyed to prevent its use by the Union Army to ship troops and supplies to Washington, DC.

The mainline of the Delaware Railroad was eventually absorbed into Conrail, created by the Federal Government to operate the potentially profitable lines of multiple bankrupt carriers.