Question: Which canal was in operation most recently, the Chesapeake and Ohio Canal or the Blackstone Canal?
Sentence (from "Chesapeake and Ohio Canal"): The Chesapeake and Ohio Canal, abbreviated as the C&O Canal and occasionally called the "Grand Old Ditch," operated from 1831 until 1924 along the Potomac River from Washington, D.C., to Cumberland, Maryland.
Relevant evidence: Yes