What was the first major improvement in the America transportation system?

The first major improvement in the American transportation system was the construction of the National Road, also known as the Cumberland Road, which began in the early 1800s. This federally funded project facilitated overland travel and commerce by connecting the eastern states to the western frontier. It was significant in promoting westward expansion and economic growth, setting the stage for further advancements in transportation, such as railroads and canals. The National Road represented a shift towards more organized and accessible transportation infrastructure in the United States.