Rachel Louise Carson (May 27, 1907 – April 14, 1964) was an American marine biologist, author, and conservationist whose book Silent Spring and other writings are credited with advancing the global environmental movement. Later in life Carson concentrated on environmental problems that she believed were caused by synthetic pesticides. The result was Silent Spring (1962), which brought environmental concerns to an unprecedented share of the American people. Although Silent Spring met with fierce opposition by chemical companies, it spurred a reversal in national pesticide policy, which led to a nationwide ban on DDT and other pesticides, and it inspired a grassroots environmental movement that led to the creation of the U.S. Environmental Protection Agency. Carson was posthumously awarded the Presidential Medal of Freedom by Jimmy Carter.