Provide your students with handwritten letters from three young students to then U.S. Senator Gaylord Nelson of Wisconsin, written a few months prior to the first celebration of Earth Day on April 22, 1970. These primary source historical documents can be a part of upper elementary students' exploration of civic activism in the service of environmental change. In this article, the authors outline a civics and history lesson in which fifth grade students explore how everyday Americans responded to the mounting environmental problems that faced our country in the 1960s. Spurred to action out of frustration over the nation's environmental practices and policies, 20 million Americans participated in the first Earth Day in 1970, the largest demonstration in our nation's history. The civic actions presented in this story of environmental activism highlight the variety of ways citizens of all ages (including children) can effect change in our democracy. The analysis of primary sources helps students understand that "democratic principles are not self-evident but require the work of an engaged and informed citizenry."