Prior to 1869, Catholics for over 1000 years had followed rules covering Abortion. These rules were incorporated into the English Common Law during the Middle Ages. In Roe vs Wade, these rules were given Constitutional status. If you want to read the rule see Roe vs Wade:
http://caselaw.lp.findlaw.com/scripts/getcase.pl?court=us&vol=410&invol=113I quote Roe vs Wade (To moderators, this is an official legal opinion of the US Supreme Court and as such NOT COPY WRITABLE and thus can be re-printed in length):
"The common law. It is undisputed that at common law, abortion performed before "quickening" - the first recognizable movement of the fetus in utero, appearing usually from the 16th to the 18th week of pregnancy 20 - was not an indictable offense. 21 The absence <410 U.S. 113, 133> of a common-law crime for pre-quickening abortion appears to have developed from a confluence of earlier philosophical, theological, and civil and canon law concepts of when life begins. These disciplines variously approached the question in terms of the point at which the embryo or fetus became "formed" or recognizably human, or in terms of when a "person" came into being, that is, infused with a "soul" or "animated." A loose consensus evolved in early English law that these events occurred at some point between conception and live birth. 22 This was "mediate animation." Although <410 U.S. 113, 134> Christian theology and the canon law came to fix the point of animation at 40 days for a male and 80 days for a female, a view that persisted until the 19th century, there was otherwise little agreement about the precise time of formation or animation. There was agreement, however, that prior to this point the fetus was to be regarded as part of the mother, and its destruction, therefore, was not homicide. Due to continued uncertainty about the precise time when animation occurred, to the lack of any empirical basis for the 40-80-day view, and perhaps to Aquinas' definition of movement as one of the two first principles of life, Bracton focused upon quickening as the critical point. The significance of quickening was echoed by later common-law scholars and found its way into the received common law in this country.
Whether abortion of a quick fetus was a felony at common law, or even a lesser crime, is still disputed. Bracton, writing early in the 13th century, thought it homicide. 23 But the later and predominant view, following the great common-law scholars, has been that it was, at most, a lesser offense. In a frequently cited <410 U.S. 113, 135> passage, Coke took the position that abortion of a woman "quick with childe" is "a great misprision, and no murder." 24 Blackstone followed, saying that while abortion after quickening had once been considered manslaughter (though not murder), "modern law" took a less severe view. 25 A recent review of the common-law precedents argues, however, that those precedents contradict Coke and that even post-quickening abortion was never established as a common-law crime. 26 This is of some importance because while most American courts ruled, in holding or dictum, that abortion of an unquickened fetus was not criminal under their received common law, 27 others followed Coke in stating that abortion <410 U.S. 113, 136> of a quick fetus was a "misprision," a term they translated to mean "misdemeanor." 28 That their reliance on Coke on this aspect of the law was uncritical and, apparently in all the reported cases, dictum (due probably to the paucity of common-law prosecutions for post-quickening abortion), makes it now appear doubtful that abortion was ever firmly established as a common-law crime even with respect to the destruction of a quick fetus. ......
It is thus apparent that at common law, at the time of the adoption of our Constitution, and throughout the major portion of the 19th century, abortion was viewed with less disfavor than under most American statutes currently in effect. Phrasing it another way, a woman enjoyed a substantially broader right to terminate a pregnancy than she does in most States today. At least with respect to the early stage of pregnancy, and very possibly without such a limitation, the opportunity <410 U.S. 113, 141> to make this choice was present in this country well into the 19th century. Even later, the law continued for some time to treat less punitively an abortion procured in early pregnancy......
It should be sufficient to note briefly the wide divergence of thinking on this most sensitive and difficult question. There has always been strong support for the view that life does not begin until live birth. This was the belief of the Stoics. 56 It appears to be the predominant, though not the unanimous, attitude of the Jewish faith. 57 It may be taken to represent also the position of a large segment of the Protestant community, insofar as that can be ascertained; organized groups that have taken a formal position on the abortion issue have generally regarded abortion as a matter for the conscience of the individual and her family. 58 As we have noted, the common law found greater significance in quickening. Physicians and their scientific colleagues have regarded that event with less interest and have tended to focus either upon conception, upon live birth, or upon the interim point at which the fetus becomes "viable," that is, potentially able to live outside the mother's womb, albeit with artificial aid. 59 Viability is usually placed at about seven months (28 weeks) but may occur earlier, even at 24 weeks. 60 The Aristotelian theory of "mediate animation," that held sway throughout the Middle Ages and the Renaissance in Europe, continued to be official Roman Catholic dogma until the 19th century, despite opposition to this "ensoulment" theory from those in the Church who would recognize the existence of life from <410 U.S. 113, 161> the moment of conception. 61 The latter is now, of course, the official belief of the Catholic Church. As one brief amicus discloses, this is a view strongly held by many non-Catholics as well, and by many physicians. Substantial problems for precise definition of this view are posed, however, by new embryological data that purport to indicate that conception is a "process" over time, rather than an event, and by new medical techniques such as menstrual extraction, the "morning-after" pill, implantation of embryos, artificial insemination, and even artificial wombs. 62 ......
To summarize and to repeat:
1. A state criminal abortion statute of the current Texas type, that excepts from criminality only a life-saving procedure on behalf of the mother, without regard to pregnancy stage and without recognition of the other interests involved, is violative of the Due Process Clause of the Fourteenth Amendment.
(a) For the stage prior to approximately the end of the first trimester, the abortion decision and its effectuation must be left to the medical judgment of the pregnant woman's attending physician.
(b) For the stage subsequent to approximately the end of the first trimester, the State, in promoting its interest in the health of the mother, may, if it chooses, regulate the abortion procedure in ways that are reasonably related to maternal health.
(c) For the stage subsequent to viability, the State in promoting its interest in the potentiality of human life <410 U.S. 113, 165> may, if it chooses, regulate, and even proscribe, abortion except where it is necessary, in appropriate medical judgment, for the preservation of the life or health of the mother.