This article analyzes constitutional decisions concerning abortion in the United States and Germany, their evolution over time, and their influence across jurisdictions. But rather than assume the existence of constitutional law on abortion, it asks how abortion was constitutionalized. The article proceeds in three sections. Section I briefly considers developments in the 1960s and 1970s, a time when reformers of many kinds persuaded legislatures around the world to liberalize access to abortion; when a mobilizing feminist movement first claimed that repeal of abortion restrictions was required as a matter of justice for women; when those who sought to preserve abortion's criminalization began to mobilize against change in the name of a ‘right to life’; and when courts in five nations first issued judgments explaining what forms of abortion regulation their respective constitutions required or allowed. Section II examines key constitutional decisions in the United States and Germany which together illustrate differences and similarities in the logic of constitutionalization. Section III looks to the logic of constitutional law today, considering how several dominant frameworks address the woman question.