Restored Roundhouse. A wide variety of equipment is seen within the roundhouse at the B&O Railroad Museum. The building was part of the railroad's Mount Clare Shops, founded in 1829, wh... (more)

Hallowed Ground: the interior of the 1884 Mount Clare roundhouse of the Baltimore & Ohio Railroad, now home to the B&O Railroad Museum, Baltimore. On the right is B&O 4-4-0 No. 25 (Mason Machine ... (more)

B&O Locomotive #25 - "William Mason." On display in the roundhouse gallery of Baltimore's B&O Railroad Museum is one of the oldest examples of a classic, 4-4-0 "American Stan... (more)

The Baltimore and Ohio Railroad Museum's prized 4-4-0 No. 25, an 1856 Mason Machine Works survivor is seen here at the Museum's back shop undergoing its mandatory 1472 service inspection and overh... (more)

The B&O #25 - the "William Mason" is America's oldest operational steam engine. She is seen here under steam at the &O Railroad Museum on a beautiful Fall day making short solo runs by the Museum... (more)

A Civil War soldier gives salute to the B&O #25, the "William Mason", America's oldest operational steam engine (built in 1856) during the B&O Railroad Museum's Railfest Steam Days.

With a camera crew in the cab and on the ground producing a documentary, the B&O 25 makes all the sound and fury she can muster on an early morning run.

Over 150 years old, B&O 25, The William Mason, can still put on a show, as it did last year passing the passenger car shops during the B&O Railroad Museum's Steam Days.

the "William Mason" on its return from Camp Carroll and a Civil War Encampment.