Who is Alexis de Tocqueville from Signs of Life in the U.S.A. and what is their importance?

Alexis de Tocquerville was a French aristocrat who wrote on the subjects of economics and philosophy. He visited New York in May of 1831 and commented on the contradiction he detected in American society - everyone is equal but trying to become a member of the elite class. His interpretation of the American dream is the value system that advertisers seek to appeal to.