Southern Pacific #2472 was built by Baldwin Locomotive Works in 1921. It is a 4-6-2 Pacific type, having 4 leading wheels, 6 drivers, and 2 trailing wheels. Pacifics such as the #2472 where designed primarily for high-speed passenger train service where sustained high speeds were just as important as pulling capability. Pacifics were used on railroads around the world and could be seen in the rosters of a great many American railroads. Southern Pacific classed the 2472 as a P-8, along with 14 sister engines built from the same Baldwin order.

The 2472's first assignments were passenger trains on the Overland Route between Ogden, Utah and Oakland, California. Crews appreciated the smooth ride afforded by the engines of its class. Overland Route runs used the same engine without change for 500 miles.

When larger and more powerful Mountain type engines (4-8-2) replaced Pacifics on long runs, the Pacifics were relegated to locals and commute service, particularly the San Francisco - San Jose run. This is where many remember seeing the #2472 performing its daily chores.

The #2472 served for almost 36 years on the Southern Pacific. The end came in 1957 when diesels had replaced almost all steam engines on the SP. Fortunately, the #2472 was saved from the scrapper's torch and was put on display in San Mateo's County Fairgrounds. It sat there until 1976 when the a group of determined volunteers decided to restore it.