Steam is produced by a boiler in the engine, which is then sent into a cylinder that contains a piston onto which the steam puts pressure until it moves and in turn moves the machinery attached to it. Once the piston has moved its full cycle, a valve opens releasing the cooler steam out into the air outside of the cylinder. This release of steam allows the piston to return to its original position so that the process can be completed.
The birth of the steam engine played a large role in the industrial age that occurred in the 1800s. The railroad had existed before steam engine trains began to be used, but they involved the carts being pulled by horses or other manual means down the tracks. With the invention of the steam engine, the trains were able to move greater loads and even transport people. They could also travel greater distances much faster. This meant that supplies could get to towns faster and people could venture farther into unsettled territories and still be able to get the supplies they needed to survive. The steam engine and the railroad were among the largest factors of the successful and rapid growth of the western parts of the United States.