Here’s a bit of trivia that might surprise you: the original Earth day had no ties to conservation. It was just meant to celebrate the first day of spring and the earth’s equinox, March 22. It had a peaceful, easy, California laid-back feeling to it—started by a guy in San Francisco in the late 1960s. I’m guessing the San Francisco link didn’t surprise you—after all, San Francisco is the City of Saint Francis, patron saint of ecology.

So when did it go from an environmental celebration on March 22 to a global event celebrated in 175 countries every year? On April 22? Excellent question.

Senator Gaylord Nelson instituted Earth Day after he took a trip to California following an oil spill and was outraged by the devastation and lack of political response. He saw this as a crisis that needed to be addressed and proposed that each university in the country set aside a day to participate in a teach-in about the environment.

The first Earth Day marked the beginning of the modern environmental movement. Approximately 20 million Americans participated in protests against oil spills, polluting factories, pesticides, loss of wilderness, and other issues. Walter Cronkite even anchored an hour-long primetime special for CBS News.

Since Earth Day started out on college campuses, it was decided that the date should fall within the third week of April because it wouldn’t interfere with Spring Break or final exams. They also figured that the weather had a higher chance of being decent so students were likely to be in class. Paying attention.

How about you? Is there something about your environment that has caught your attention lately? If so, what can you do about it? Every drop counts. Drop by drop.