Engine No. 3003 was an S-4 Hudson class passenger locomotive, the fourth engine built by the Baldwin Locomotive Works for the Chicago, Burlington and Quincy Railroad in 1930, when it was regarded as state of the art and the ultimate in rail passenger travel. The steam-powered engine pulled passenger trains at speeds up to 90 mph and was capable of 120 mph, and the locomotive and tender together weighed 364 tons. The Hudson 4-6-4 improved on steam locomotive designs by the American Locomotive Company and was first used in 1927 by the New York Central, whose mainline along the Hudson River gave the type its name. These locomotives were considered a major technological achievement, made possible by the commercial development of the outside bearing four-wheel radial trailing truck and greater power output from very large fireboxes. No. 3003 carried 24 tons of coal and 15,000 gallons of water, could haul a heavy train 500 miles without more coal, and needed two additional 15,000-gallon water resupplies on such a run. The CB&Q ordered twelve S-4 Hudson locomotives, numbered 3000 through 3011, and No. 3003 operated on the CB&Q mainline for nearly 20 years before more efficient diesel engines replaced it. It was dedicated to the City of Burlington in 1961 and refurbished and rededicated in November 1991. The surrounding area was historically known as Market Square. In 1868 the Burlington and Missouri Railroad and the Chicago, Burlington and Quincy jointly built the first Union Depot near this location as a two-story wooden structure; in the 1880s it was moved two blocks west to Fourth and Elm Streets and converted to a home. A second Union Depot, a single-story building with hotel and dining room facilities, was built behind the first depot here. As passenger travel increased, a third Union Station in the Victorian style was built south of here, but it was destroyed in a fire on January 20, 1943. During World War II, the railroad had to apply to the War Production Board for authority to construct a replacement depot, so a temporary wooden depot was built north of here until the existing flagstone depot opened and was dedicated on March 28, 1944. The sand tower displayed with the locomotive originally stood near a roundhouse and other railroad facilities along the river near the foot of Locust Street.