In 1782, soon after the United States won its independence, the bald eagle was chosen as the national bird of the new country. American leaders wanted the eagle to be a symbol of their country because it is a bird of strength and courage. They chose the bald eagle because it was found all over North America and only in North America.
But a little over 200 years later, the bald eagle had almost disappeared from the country. In 1972, there were only 3,000 bald eagles in the  layaffectspollutionhatchdecreasingentiresurviveprotect United States. The reason for the bird's  affectsdecreasingsurvivepollutionprotectlayentirehatch population was  decreasingprotectaffectspollutionsurvivehatchentirelay, especially pollution of the rivers by pesticides. Pesticides are chemicals used to kill insects and other animals that attack and destroy crops. Unfortunately, rain often washes pesticides into rivers. Pesticides pollute the rivers and poison the fish. Eagles eat these fish, and the poison  surviveprotectpollutiondecreasinglayhatchentireaffects their eggs. The eggs have very thin shells and do not  laysurvivedecreasingentireprotectpollutionaffectshatch. Eagles  hatchsurviveentiredecreasingprotectaffectspollutionlay only two or three eggs a year. Because many of the eggs did not hatch and produce more eagles, the number of eagles quickly became smaller.
Today, the American government and the American people are trying to  decreasinghatchpollutionlaysurviveentireprotectaffects the bald eagle. The number of bald eagles is increasing. It now appears that the American national bird will  pollutionprotectentirehatchdecreasingaffectssurvivelay and remain a symbol of strength and courage.