Cables are what make all of our connections possible; everything from your internet to you TV is possible thanks to cables that span the globe.
Cable lines, or in those days, phone lines were the hottest technology. Below is a map from 1901 of undersea cables that connected the world to each other. With these cables the world was finally able to communicate to each other quickly and was no longer dependent on mail.
Moving forward to 2008 and nearly everyone in the world depends on undersea cable. Everything from your favorite website to that spam mail you received from a rich king in Nigeria who wants to give you his fortune are dependent on these undersea cables.
There is no doubt that as we move forward in the future that we will require more cables to be put on the sea floor. Imagine what the next 100 years will bring for undersea cables, or perhaps a new technology will rid our need for them completely.