U.S. News and National Top Stories NPR coverage of national news, U.S. politics, elections, business, arts, culture, health and science, and technology. Subscribe to the NPR Nation RSS feed.

Libyan Foreign Minister Moussa Koussa speaks during a press conference in Tripoli on March 19. Koussa arrived in Britain on March 30, and told the British government that he was resigning from his post. Mahmud Turkia/AFP/Getty Images hide caption

toggle caption
Mahmud Turkia/AFP/Getty Images

A map shows birth rates in America by state, from 2007 to 2009. National Center for Health Statistics hide caption

toggle caption
National Center for Health Statistics

Secretary of Defense Robert Gates (left) and Chairman of the Joint Chiefs of Staff Admiral Mike Mullen testify before the House Armed Services Committee on Thursday about Operation Odyssey Dawn. Saul Loeb/AFP/Getty Images hide caption

toggle caption
Saul Loeb/AFP/Getty Images

A view of the Three Mile Island power plant near Harrisburg, Pa., site of the worst nuclear accident in U.S. history. In 1979, a reactor at the plant experienced a partial meltdown, but radioactive material never escaped containment. Bradley Bower/AP Photo hide caption

toggle caption
Bradley Bower/AP Photo