Abstract: This is a complete but unfinished draft of an article on the history of American family law. The first part describes four stages in the legal conceptualization of the family in the U.S. over the period from the late 18th century to ca. 1960. It is part of a larger intellectual history project depicting the stages of American legal consciousness as a whole. In this part, I treat the socio-economic background and the political struggles that shape and are shaped by consciousness as context for the story of conceptual change. In the second longer part of the piece, I present the interaction of political forces with legal consciousness (as evolved in Part One), along with social, economic and cultural change, in a single narrative of the historic transformation of American family law doctrine, ca. 1950-2015. This part defines family law broadly to include rules about marriage and parenthood along with social welfare law and the law of sex and reproduction, and includes their constitutionalization. It is in the tradition of political economy, starting with conflicting groups led by elites, understood not just as collections of individuals but as loose collectives with goals and strategies that are based on shared material and ideological interests. An important theme is the influence on legal change of tacit pro-sex and neo-puritan attitudes within the law making elites.