After the last question, it's a pleasure to receive one I can actually answer! Julie, from the Finger Lakes region of New York state (here in the U.S.) asks,
How long did it take to build the Erie Canal?
Thank heaven for Wikipedia! There, I learned:
The Erie Canal was first proposed in 1807, it was under construction from 1817 to 1825 and officially opened on October 26, 1825