The most important invention of the 20th century

What is the most important invention of the 20th century? There are a handful of very obvious candidates: the computer, the cell phone, and the television. These were all clearly revolutionary devices that have changed the way we live our lives. Most notably they have all shrunk the world and been major factors in the way we receive information. Another obvious candidate is the Internet, which is difficult comprehend the scope of it's impact at such an early stage. However, I think a strong argument can be made for an invention that has changed our lives more than any of these items. In fact one might say that were it not for this invention the technological landscape as we know it would be vastly different. The item I am thinking is likely something you see on a daily basis, but do not interact with. You are directly affected by it's existence, but probably have never touched one. It's beauty does not lie in it's complexity, but rather it's simplicity. I am referring to the intermodal container. What is that, you ask? These are the standard sized, corrugated metal containers that travel by train, truck, and ship all over the world. In 1955 a former trucking company owner designed the first container and this design continues to be used today in ports around the world. Previously containers were made of wood and were difficult to stack. Malcolm McLean's container was certainly stronger than the wooden ones and solved the problem of how to lift containers securely by incorporating a simple locking mechanism on each of the containers eight corners. With the advent of containerization that was sturdy and reliable there would be a surge in imports and exports. "Made in China" might never have existed without the intermodal container or it at least wouldn't have existed at the price point that it does now.