In 1957, when Fortune prepared its first list of the wealthiest Americans, it estimated that Ailsa Mellon Bruce, her brother, Paul, and her cousins, Sarah Mellon and Richard King Mellon, were all among the richest eight people in the United States, with fortunes of between 400 and 700 million dollars each. In 1968, Ailsa and Paul donated $20 million to build an annex to the National Gallery of Art in Washington, D.C.[1][4]