The second half of the 19th century proved a prolific period for marine steam propulsion. Shipbuilders introduced innovative solutions to earlier problems with each new ship they built. They eliminated the need for paddlewheels, turned to iron and later steel for hull construction, and significantly improved the steam engine.
The first steamship credited with crossing the Atlantic Ocean between North America and Europe was the American ship SS Savannah, though she was actually a hybrid between a steamship and a sailing ship, with the first half of the journey making use of the steam engine. The SS Savannah left the port of Savannah, Georgia, on May 22, 1819, arriving in Liverpool, England, on June 20, 1819; her steam engine having been in use for part of the time on 18 days (estimates vary from 8 to 80 hours). A claimant to the title of the first ship to make the transatlantic trip substantially under steam power is the British-built Dutch-owned Curacao, a wooden 438 ton vessel built in Dover and powered by two 50 hp engines, which crossed from Hellevoetsluis, near Rotterdam on 26 April 1827 to Paramaribo, Surinam on 24 May, spending 11 days under steam on the way out and more on the return. Another claimant is the Canadian ship SS Royal William in 1833.