Here are some resources from the U.S. Government about Earth Day and the environment:
Earth Day - US Government Portal
Earth Day from Environmental Protection Agency (EPA)
U.S. Fish and Wildlife Service (USFWS) - Earth Day 2009
Energy Efficiency and Renewable Energy: Earth Day (U.S. Department of Energy)
Remarks at the State Department's "Greening Diplomacy" Earth Day Event
The White House - Press Office - Presidential Proclamation - Earth Day
Earth Day Resources from Library of Congress