The Southern Pacific Railroad Company is dictated to much of what happened in this town for 75 years after the train's 1880 arrival. By the transformative 1960s, though, the importance of the railroad was declining. To illustrate Tucson's railroad history, the small and informative Southern Arizona Transportation Museum offers visitors a trip through those times. Using photos, maps, artifacts and video displays, the museum shows why the tracks originally came to Tucson, and what that meant to the community. The biggest display item is historic locomotive No. 1673, a steam engine dating back to 1900. The eyes of youngsters and their parents during a Saturday-morning outing to the museum will instantaneously light up when they see this massive piece of machinery that once chugged across Southern Arizona.