Hank Aaron's contributions to society come from both from his spectacular baseball career and his humanitarian efforts off the field. In his career, he set records for the most home runs (755) and the most runs batted in (2,297). He became the first player ever to have more than 3,000 hits and more than 500 home runs. During his pursuit of these goals, he persevered despite receiving hate mail, racist comments and threats of assassination. The resilience and strength he displayed under these conditions were an inspiration to many.
Off the field, Henry Aaron has been honored for his work in forming the Hank Aaron Chasing the Dream Foundation, which awards grants to children to help them pursue special education interests. He has been a leading proponent for minority hiring in sports. Major League Baseball created the Hank Aaron award in 1999, to be given to the best offensive player each year. He was awarded the Presidential Medal of Freedom in 2002, in recognition of his accomplishments.
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http://espn.go.com/sportscentury/features/00006764.html -This article gives a very detailed account of the trials he had to endure.