Steam Train

For centuries, if not millennia, the horse and cart was the primary, if not the only, practical way of moving goods of any kind overland for a large distance. A century ago however, there was a revolution in transport. Born out of the industrial revolution, the steam train forever changed overland transportation. No longer was commerce on a large scale limited to ports, navigable rivers, and canals, though anyone living on top of a mountain or steep hill was unfortunately out of luck. 
The passage of time, and advances of technology that came with it, have produced a generation of steam locomotives that bear only a passing resemblance to "The Rocket" the world's first successful steam engine. Now they dominate Europe, North America, and much of the rest of the world, brining freight, mail, and persons from where they are, to where they, or their owners, want to go. A village can be made a town just by the presence of a railway, a town can be made a city. Though these machines need looking after, and they can only run on rails, they are essential to any modern nation's civil and military needs.
Britain was the first to embrace the steam engine and its already advanced industry leapt ahead by leaps and bounds as a result. Not without its naysayers and controversies of course, but those were soon quietened, by the profits if nothing else. Germany too, with its vast reserves of coal soon embraced them, and even the vastness of Russia was somewhat reduced by them. Though the sheer distances involved still remained huge and a burned on whoever tried to venture into the deserts of the artic, Siberia, or central Asia.
Nowadays though, it is the United States that are at the forefront of steam power. From coast to coast titanic engines pull vast trains through mountains, swamps, forests, plains, and every other kind of landscape with every kind of product and passenger such a nation can produce. How long these great machines will continue to dominate the ways of the world is an unknown. What is known, is that they will be going no where anytime soon. Except of course, to their destination.