Earth Day grew out of the environmental movement in the late 1960s in response to a series of environmental disasters that took lives, marred natural beauty and threatened animal species. An estimated 20 million Americans participated in the first Earth Day - April 22, 1970 - which consisted of a series of local events designed to raise awareness of pressing environmental concerns. Today, the environmental movement is experiencing a strong resurgence amid fears of climate change, rising sea levels and carbon emissions. Yet the issue has grown far more partisan and divisive than it was when Earth Day first began. In this Lowdown lesson plan, students will analyze the origins and history of Earth Day, as well as evaluate how political and public support for Earth Day has changed over time.