This article endeavours to understand the feminist activism from which constitutional abortion rights in Canada were born in the landmark Supreme Court case of R v Morgentaler 1988, and the influence of these rights on continued feminist activism for reproductive justice. Part I reviews abortion practice in the ‘back-alley’ prior to and immediately after the 1969 criminal reform with attention to the direct service activism of liberation feminists in their campaign to repeal the abortion law as a matter of constitutional justice. Part II turns to adjudication in the courts to study how judicial reasoning channelled these constitutional claims, exploring the continuity of ideas between feminist liberation, the criminal defence of necessity, and Charter rights to liberty and security of the person. Part III reverses perspective to examine how Morgentaler 1988 shaped and ultimately de-radicalized abortion rights and a new wave of feminist activism through the constitutional logics and institutions of markets and medicine. The article concludes by reflecting on what constitutional abortion rights may yet become, informed by a vision of reproductive justice and rooted in a collective democratic spirit. This article is a study of the feminist ideas and practices that shaped abortion rights in Canada over the 150 years of its Constitution, not least the 35 years of its Charter, and that will continue to do so into the future.