Populations of the American bald eagle — the bold national symbol of the United States — have quadrupled since 2009, according to a new report by the U.S. Fish and Wildlife Service and its partners. Bald eagles once teetered on the brink of extinction, reaching an all-time low of 417 known nesting pairs in 1963 in the lower 48 states. However, after decades of protection, the banning of the pesticide DDT, and conservation efforts with numerous partners, the bald eagle population has flourished, growing to more than 71,400 nesting pairs. .. the bald eagle population climbed to an estimated 316,700 individual bald eagles in the lower 48 states.