Although steam had been used at sea from the 1820s, paddlewheel ships were Never front-line warships. The paddlewheels and machinery were terribly Exposed, while they lacked the firepower of sailing ships and could not sail well Enough to maintain station in a sailing fleet without burning coal. By the 1840s Steam had added a new dimension to the strategic and tactical mobility of Maritime power, and were especially good instruments for amphibious power Right: a french battleship In the last days of sail, Showing the full cross Section of uses to which Every on-board space was Put.
Below: the american army Under winfield scott at vera Cruz on 9 march 1847.
Command of the sea allowed The americans to land on the Mexican coast, and take the Shortest route to the mexican Capital, much as the Conquistadors had done Three centuries before. The Route through texas was far Longer and would have taken Years of war to reach mexico City. By landing at vera cruz Scott was able to complete The task in a single campaign.