That's a win-win situation for environmentalist parents. But for children to truly appreciate the fun that could be had on Earth Day (April 22), it helps if mom and dad understand where Earth Day comes from and exactly what it's about. According to USA Today, this is the 40th anniversary of Earth Day. Back in 1970, Wisconsin Senator Gaylord Nelson, who was an environmentalist at heart, proposed that April 22 as a day set aside to honor efforts to protect the planet’s resources. The idea caught on, and later that year, Congress authorized the creation of the U.S. Environmental Protection Agency (EPA) in order to police environmental pollution.