Frederick County has been called the crossroads of history. Many people came through the area on their way elsewhere. The development of the county was greatly influenced by the roads that carried these people to other parts of the country. New transportation technology and its greater infrastructure, such as the B&O Railroad, impacted Frederick along with the growth of the trolley system and the building of the C&O Canal. We will study the history of Frederick County through the various modes of transportation, their growth, and at times, their decline.