A key goal of any civil-justice system is to allocate cases to courts in sensible and efficient ways. Most systems exhibit allocative rules that rigidly and substantially limit party choice among forums. Not so in the United States. This paper details the unique landscape of forum shopping in American courts along three dimensions: vertical shopping between federal and state court, horizontal shopping among states, and individual shopping for particular judges. It describes the legal, structural, and cultural foundations that enable and even encourage forum shopping in the United States, especially as contrasted with other countries. It then explains and assesses its persistence in American litigation culture today.