In the United States, the canal that brought about an age of canal building was the Erie Canal. It was a long-sought-after canal and connected the Great Lakes to the Hudson River.[7] This canal initiated a half-century-long boom of canal building and brought about many new features that allowed canals to be used in different areas previously inaccessible to canals. These features include locks, which allow a ship to move between different altitudes, and puddling, which waterproofed the canal.[2]