In every year since 1982, the popular magazine Forbes Magazine has published a list of the 400 wealthiest Americans. That list has attracted attention from the press and public, but it has been largely ignored by economists, at least in their professional capacities. Although a list published by a popular magazine may seem like a dubious source of data, the magazine's list is arguably the best source of data on the very top of the wealth distribution in the United States. This dissertation is a series of essays that use the magazine's list to study the wealthiest Americans. The essays study inequality between the wealthiest Americans and everyone else, inequality among the wealthiest Americans themselves, and mobility among the wealthiest Americans over time. Taken together, the essays offer insight into some basic empirical facts about a much noticed but little studied group.