A small minnow known as the Oregon chub recently became the 29th species to recover after being listed as endangered under the U.S. Endangered Species Act and the first fish to ever join those ranks. The Endangered Species Act , signed into law in 1973, is widely considered one of the most important pieces of U.S. environmental legislation ever enacted. This e360 photo gallery highlights the 21 species native to the United States, including the bald eagle (above), that have made recoveries strong enough to be removed from the endangered list.