The World Book Series
It’s difficult to remember a time before the Internet but it’s crucial to remember that it wasn’t a big deal until the late ’90s. Before we had limitless information at our fingertips we had to use other sources. Many American children grew up with the World Book Encyclopedia series.

These books informed readers about everything from different types of animals to all of the U.S. states. They continue to run today but they’re not as popular. More serious readers also collected the Encyclopedia Brittanica. However, this series went completely online in 2012 (via North Jersey).