In this half-a-century trucks went from small replacements for horse-drawn wagons to large enough to compete with railroads for freight hauling.
The world saw its first useful trucks in the 1920s. They could only haul a few thousand pounds or so, and they were often viewed as a small improvement over horse-drawn wagons for getting goods from the railroad stations to off track destinations. Twenty-eight horsepower was enough for many trucks of the day. The 1930s saw larger engines, and new designs putting the weight of the engine over the front axel. This improved weight distribution and hauling capacity.
The 1940s, and WWII produced new trucks for military purposes. Truck factories in virtually all of the industrialized countries were too busy meeting the needs of the military to give much thought to developing new civilian models. After the war, and throughout the 1950s civilian truck technology began to move forward rapidly as new ideas which had been seen or tried on the battlefield found new applications. The fuel injected diesel engine was being tried in new trucks. Diesel was a truck technology that was here to stay. Early diesel engines were only about 150-180 horsepower, but some were turbo charged. They could haul much longer and heavier loads than their predecessors.
In the 1960s America's Interstate Highways were beginning to take more and more market share in freight hauling away from the railroads. Long-haul driving was becoming popular and competing with railroads. Detachable trailers, sleeping cabins, and of course the truck stop were improving the lives of over the road drivers.
