And this is a telegraph. And then a telegraph, all of a sudden, for the first time in history, you can communicate across the globe in a mere instant. And what used to take months to figure out what was going on could now happen in seconds. So once again, this is valuable for trade, but it's also valuable for coordinating military power. So in large part to these revolutions that we're seeing, and we will study more in other videos, the map of the world looks very different roughly 150 years later. This is what the world looks like around the year 1900. And you immediately notice some differences from that previous map.