1833 ( June ) : The Staple Bend Tunnel completed in June 1833 as part of the Allegheny Portage Railroad which opened in March 1834 .
The Staple Bend Tunnel is the first railroad tunnel in the U.S. .
1833 ( June ) : The Staple Bend Tunnel , the first railroad tunnel in the U.S. , completed in June 1833 as part of the Allegheny Portage Railroad which opened in March 1834 .