Look around the room you're sitting in.
Chances are that almost everything in it, from your phone to your shoes, spent part of its life inside a steel box.
The shipping container is so ordinary that we hardly notice it, yet it has quietly reshaped the world economy.
Before the 1950s, loading a cargo ship was slow, expensive work.
Dockworkers carried sacks, barrels and crates on board one by one, and a single ship could sit in port for a week or more.
Goods were often damaged, and some simply went missing along the way.
The man who turned this system on its head was Malcom McLean, a trucking businessman from North Carolina.
His idea was deceptively simple: instead of unloading a truck and carrying its contents onto a ship, why not lift the whole box onto the ship?
In April 1956, a converted oil tanker called the Ideal X sailed from Newark, New Jersey, to Houston, Texas, carrying fifty-eight containers.
According to McLean's own figures, the cost of loading fell from almost six dollars a ton to about sixteen cents.
It took years for the idea to catch on.
Ports had to install enormous cranes, and companies had to agree on standard sizes so that a box from one country would fit on a train or truck in another.
Once they did, however, trade took off.
Today, the largest container ships are longer than three football fields.
The next time you open a package from the other side of the world, spare a thought for the humble steel box that brought it to your door.