A wagon train is a convoy or group of wagons who travel together for safety. A baggage train is a military wagon train used to carry the equipment and supplies needed by an army. They needed to carry enough supplies, including feed for the draft animals, for the entire journey. Wagon trains are most closely associated with American pioneers traveling west. As the population of the Thirteen Colonies grew, people migrated westward looking for inexpensive lands and new opportunities. The wagon had to carry all the supplies for the trip and all a family's personal belongings. While military use of wagon trains is ancient, the Romans built a network of roads for their armies and baggage trains to move throughout the empire.