context: With regulations in place and DDT banned, the eagle population rebounded. The bald eagle can be found in growing concentrations throughout the United States and Canada, particularly near large bodies of water. In the early 1980s, the estimated total population was 100,000 individuals, with 110,000–115,000 by 1992; the U.S. state with the largest resident population is Alaska, with about 40,000–50,000, with the next highest population the Provinces and territories of Canada of British Columbia with 20,000–30,000 in 1992. Obtaining a precise count of bald eagles population is extremely difficult. The most recent data submitted by individual states was in 2006, when 9789 breeding pairs were reported. For some time, the stronghold breeding population of bald eagles in the lower 48 states was in Florida, where over a thousand pairs have held on while populations in other states were significantly reduced by DDT use. Today, the Contiguous United States with the largest number of breeding pairs of eagles is Minnesota with an estimated 1,312 pairs, surpassing Floridas most recent count of 1,166 pairs. 23, or nearly half, of the 48 contiguous states now have at least 100 breeding pairs of bald eagles. In Washington State, there were only 105 occupied nests in 1980.  That number increased by about 30 per year, so that by 2005 there were 840 occupied nests. 2005 was the last year that the Washington Department of Fish and Wildlife counted occupied nests. Further population increases in Washington may be limited by the availability of late winter food, particularly salmon.
question: What helped to save the population of bald eagles in the United States?
answer: regulations