Short answers, pulled from the story.
Francis Egerton, the 3rd Duke of Bridgewater, owned the coal mines in Worsley. He sought a better transport method because existing options like packhorses and river navigation were inefficient and expensive.
Work commenced in September 1760 after James Brindley surveyed the route for 46 days. The first boat crossed the canal on the 17th of July 1761.
The duke invested £168,000 in the scheme from Worsley to Manchester. This investment covered the construction of underground tunnels and an aqueduct at Barton-upon-Irwell.
The connection to the Mersey opened on the 1st of January 1773. Engineers constructed ten locks to lower water from the Runcorn basin which sat almost 50 feet above the river.
Construction of the ship canal forced the removal of the original Barton Aqueduct. It was replaced by the Barton Swing Aqueduct to accommodate larger vessels.
Commercial freight traffic continued until 1975 when the last regular cargo of grain moved from Liverpool to Manchester for BOCM. Pleasure craft have been allowed on the canal since 1952.