The cost of building the new route, especially the Howard Street Tunnel on the connecting Baltimore Belt Line, led to the B&O's first bankruptcy.

It acquired the Delaware Western Railroad, which had a charter but no track, merged it into the Baltimore & Philadelphia in 1883, and began construction.

At the Philadelphia end, the new line crossed the PW&B and its old alignment (part of the Philadelphia and Reading Railway's branch to Chester) and crossed to the east side of the Schuylkill River on the new B&O Railroad Bridge, just south of the Grays Ferry Bridge.

[5]: 27, 31, 39–41 The Reading, originally using the Junction Railroad west of the Schuylkill to access its Chester branch, obtained trackage rights over the Baltimore and Philadelphia, and the B&O obtained trackage rights over the Reading's lines from Philadelphia to Jersey City, New Jersey, across the Hudson River from New York City.

extending both north and south of a connection to the main line at Eddystone, Pennsylvania along Crum Creek.

from the east end of Wilsmere yard (later, from Elsmere Junction) into Wilmington, Delaware to a station at Market Street.

Finished to a paper mill in Providence; a small amount of grading done to the north towards Oxford, Pennsylvania.