(Gustav[at the top] is the largest canon in the world. So large that it had to be transported on two sets of rails)
Roads of rails called Wagonways were being used in Germany as early as 1550. These primitive railed roads consisted of wooden rails over which horse-drawn wagons or carts moved with greater ease than over dirt roads. Wagonways were the beginnings of modern railroads.
By 1776, iron had replaced the wood in the rails and wheels on the carts. Wagonways evolved into Tramways and spread though out Europe. Horses still provided all the pulling power. In 1789, Englishman, William Jessup designed the first wagons with flanged wheels. The flange was a groove that allowed the wheels to better grip the rail, this was an important design that carried over to later locomotives.
Although there were some "railroads" existing before 1804 they were either horse or man powered. The age of the modern railroad began with the invention of the steam engine. In 1804 a high-pressure steam engine was mounted on a four-wheeled vehicle designed to run along a track, and carried 9 metric tons (19,800 pounds), 5 wagons and 70 men. In 1830 the first passenger service was begun. The "iron horse" had arrived.