The original Erie Canal was completed in 1825. It was forty feet wide by four feet deep with 77 locks.
The State of New York completely rebuilt the canal from 1905-1918. The new canal has a minimum bottom width of 75 feet and a depth of 12 feet with only 57 locks. It does not follow the original route in many places. A more complete history of the canal may be found here: http://www.canals.state.ny.us/cculture/history/finch/index.html
Today, the canal is used primarily for pleasure boating.