The Wilmington and Northern railroad was formed in 1866 as the Wilmington and Brandywine Railroad from two other shortlines, the Delaware and Pennsylvania and the Berks and Chester Railroad. It opened between Wilmington and Poplar Neck (Schyulkill River crossing south of Reading, PA) in 1871. In 1877 it was reorganized as the Wilmington and Northern Railroad. The DuPont family of Wilmington, DE were major financial supporters. The Philadelphia and Reading Railroad gained control in 1898 and the W&N was leased to the P&R for 999 years in 1900.
The W&N was part of the P&R, RDG Wilmington and Columbia Division, later becoming part of the RDG Reading Division.
Flooding from Hurricane Agnes severed the line in 1972. The portion between Birdsboro and Reading was operated by the RDG and then CR. The portion from Birdsboro to Trap Rock was operated by the quarry at Trap Rock. The portion from Valley (Coatesville) to Elsmere Jct. (Wilmington) was operated by the Delaware Valley Railroad and then in 1981, the Brandywine Valley Railroad (owned by the steel mill at Coatesville).