Salafism, a complex and multifaceted conservative global Islamic movement, has become a topic of increased interest among a range of scholars over the last decade. Although worthy of study in its own right, the Salafi movement often attracts attention because certain components of it provide much of the ideological inspiration for jihadist groups including al-Qaeda and the Islamic State (IS). This study is one of the first to focus solely on Salafism in the United States. Drawing on multiple primary sources, including interviews with leading American Salafis, it provides an overview of the history, evolution, and contours of the movement in America. In doing so, it also offers insights on the genesis of jihadism in the U.S.