I am looking for any tunnels built before the American Civil War (April, 1861) that are still in railroad service.

TVRM's was completed in 1858.

Here are at least two of what I am sure are many more:

Norwich & Worcester's Bundy Hill Tunnel 1837 (substantially original, now P&W)
B&O's Henryton Old Main Line MP23 430 feet Brick 1850 (modified 1865, 1903)

Reading company Flat Rock Tunnel
In 1839, Flat Rock Tunnel was completed and by 1842, the Philadelphia and Reading Railroad had freight and passenger service from Philadelphia to Pottsville.

http://www.catskillarchive.com/rrextra/abrw10.Html

The Reading has several built befor the Civil War.

A tunnel built by the Baltimore and Ohio, named Doe Gully, located about sixty miles west of Harper's Ferry, for the purpose of avoiding a circuitous bend of the Potomac river. It was built in 1839-41. Its length was 1,207 feet, and its cost was $98,426. Another tunnel was built by the same company, at Harper's Ferry, in 1839-40, 86 feet in length, which cost $4,386. A tunnel built by the New York and Harlem, called "Old" Harlem Tunnel, in 1836-37, 844 feet in length. A tunnel built by the Harrisburg, Portsmouth, Mount Joy and Lancaster Railroad Company, on a line which now forms part of the Pennsylvania Railroad system, in 1835-38, named Elizabethtown, 900 feet in length. The Black Rock Tunnel, built by the Philadelphia and Reading Railroad Company, in 1835-37, near Phoenixville, 1,932 feet in length, which cost $178,992. The Flat Rock Tunnel, built by the same company, at Manayunk, in 1840, 937 feet in length. The Pulpit Rock Tunnel, built by the same company, in 1839-41, at Port Clinton, 1,637 feet in length, which cost $116,728. The Summit Tunnel, built by the Catawissa and Williamsport Railroad, at Summit Station, in 1838, 1,050 feet in length. The Sherman's Tunnel, built by the same company, in 1838, 377 feet in length.

Howard Tunnel, Northern Central/PRR between York and New Freedom, PA, 1838--track currently OOS, but tunnel still used for bike trail.

Marriottsville Tunnel on B&O Old Main between Baltimore and Harpers Ferry, built ca. 1850, enlarged 1866-ish and again in 1903, now called Hen ryton Tunnel.

Harpers Ferry's and Point of Rocks' tunnels were built after the Civil War.

DL&W Nay Aug tunnel, completed in 1856. In use by the Delaware-Lackawanna RR and Steamtown excursions. Modernized facade on West end gives the appearance of a younger bore, but its the original and still in use. A second bore, from 1905, has been abandoned since the flood of 55.

Elizabethtown was bypassed by a cut a few feet South and higher, long before PennCentral. Flat Rock is across the Schuykill River from Manayunk in West Manayunk, now gentrified to Belmont Hills. Pulpit Rock was bypassed long ago. Sherman's spelled Shumans was abandoned when ConRail didn't acquire it. Summit, also called Lofty, was used, but not owned, by ConRail for about 2 years until the subsidy ran out.
Almost any tunnel on the Main Line of the Pennsylvania RR between Pittsburgh and Philadelphia is pre-Civil War, although some have newer parallel bores.
Old tunnels abandoned long ago could be another topic.

PRR:

Allegheny Tunnel, just west of Altoona Pa, circa 1854.

Possibly New Portage Tunnel, near the same location and date(?)

John R.

Hi,
The Western & Atlantic bore that Andrews Raiders intended to distroy using the General is still in existance but has a parallel bore used by CSX now.
The TVRM uses a pre-Civil War bore.
Doug