Twain and the Steam Engine" ... all the thousand willing and handy servants of steam and electricity were working their way into favor. We had a steamboat or two on the Thames, we had steam war-ships, and the beginnings of a steam commercial marine; I was getting ready to send out an expedition to discover America" (Twain 270).
In 1753 the North American colonies saw the arrival of a machine that would bring incredible change: the first steam engine, later the symbol of the Industrial Revolution. It was so new that its owner ordered all its parts in triplicate, realizing that if anything broke, there would be no way to repair it locally (Cowan 74).
As transportation systems developed enough to ensure a steady supply of coal, and as steam engines became safer, factories began replacing millwheels: steam engines were more powerful, reliable, and convenient (Gordon and Malone 103). New, larger factories were built in the city, where the workers were, instead of always being by a river. Samuel Slater built a steam-powered textile mill in Providence, Rhode Island, in 1827. That mill was the first to mass-produce textiles in America (Gordon and Malone 165). Some mills continued to use their water wheels but depended upon steam engines for additional power and heat (Gordon and Malone 166). America gradually became less agrarian and more urban and industrial.
Steam engines generated a great deal of air pollution. While many people in the late 1800s considered the dark smoke as a sign of "progress," others saw it as dirty and a health hazard. Twain himself commented that "in St. Louis, and in London and Pittsburgh, you can't persuade a thing to look new; the coal-smoke turns it into an antiquity the moment you take your hand off it" (Gordon and Malone, 166-67). Once electrical power was more widespread, determined efforts to clean up the air met with more success. In Pittsburgh today, for example, the uncleaned buildings of the University of Pittsburgh are the only major reminder of this beautiful city's earlier dark skies.
Steam engines also made possible both steamboats and the railroad. Twain's love affair with steamboats has been well documented in his autobiography, Life on the Mississippi, and by others. By the time Twain published Connecticut Yankee, travel by steamboat was common, and the country was linked by railroad coast-to-coast. It was possible to travel from the East Coast to the West Coast by rail in about a week. Advertisements from the time period promote rail travel as safe, comfortable, even luxurious (Blaszcznyk).
Because the steam engine brought so many changes to America, it is understandable that Twain would use it in his novel to transform England in a similar way.
These links provide additional information: