Three rail lines largely contributed to Rockdale's early commercial development, and of the three, the International & Great Northern (I&GN) made the biggest impact. This former I&GN passenger depot opened in 1906. It survived various changes to the rail company, including its transition to the Missouri Pacific line in 1956. After years of declining rail use by passengers, the last passenger train left the depot on September 21, 1970, and the building served as storage for many years. Restored at the turn of the 21st century, the depot is eclectic in design with elements of Italianate, Queen Anne and Prairie styles of architecture. Recorded Texas Historic Landmark - 2005