Although primarily a Proper Philadelphia story that starts with the city's Golden Age at the close of the eighteenth century, this classic study of an American business aristocracy of colonial stock and Protestant (largely Episcopalian) affiliations is also an analysis of how fabulously wealthy, nineteenth-century family founders in Boston, New York, and Philadelphia supported a series of class-creating institutions outside the family. These institutions included: the New England boarding schools; Harvard, Yale, and Princeton; and urban men's clubs and suburban country clubs. They produced, in the course of the twentieth century, a national, intercity, upper-class way of life. Philadelphia Gentlemen shows how this class reached its peak of power and influence in America on the eve of the Second World War. The quantitative backbone of the book is based on the 770 Philadelphians of various class and ethnicn backgrounds listed in Who's Who in America in 1940, an index of the elite leadership structure; 226 members of this elite also came from upper-class families listed in the Social Register that year. In addition, Baltzell shows howthese upper-class members dominated the financial and business power structure of the city in 1940. Thus, although he describes the upper-class style of life in Philadelphia in fascinating detail, he constantly emphasizes that it is power and influence over the whole social structure, rather than style of life per se, that is an essential quality of a properly functioning upper class. Whenever an upper-class way of life becomes an end in itself, in other words, its usefulness is over. In an afterword, written in the 1960s and included in this edition, Baltzellshows how this is what has happened since the end of World War II.