1807, Robert Fulton's Clermont the first ship to demonstrate the feasibility of steam propulsion for commercial use, but it also carried sail.
1819, The first steamship to cross the Atlantic was the American City of Savannah, but it also carried sail.
1837, Britain's steam-powered Great Western established regular transatlantic passenger service, but it also carried sail.
1838, SS Archimedes was the first steamship to be driven by a screw propeller, but it also carried sail.
1871, The first British Navy ship not to carry masts or expensive sails the H.M.S. Devastation..
Commercial steam ships regularly carried masts and auxiliary sails into the 20th century (1900s).
Question:
IF steam power was superior to sail, Why did it take nearly 100 years for commercial ships to abandon sail after steamships were demonstrated?.