Author Burke Davis in his book "The Civil War, Strange and Fascinating Facts", Fairfax Press, 1982, writes of this incident in the last of this book.

He doesn't document any primary sources for his story. BUT, on the Discovery Channel T.V. program "Mythbusters" they examined the particulars of this story in a fair amount of detail and determined that such a rocket could have been built using technology available at the time.

They actually built a working rocket and fired it off. It didn't quite preform as well as it should have. It didn't go that far, certainly not 100 miles. BUT, they didn't exactly reproduce the Cannon barrel and guncotton launching system either.