and other teachings of the Catholic Church till 1869. Abortion, prior to 1869 was viewed as a venial sin (i.e. not a violation of any of the ten Commnadments). Mortal sins are acts that violate one or more of the Ten Commandments (Adultry is a Mortal sin, Lying under oath to hurt someone is a mortal sin {Clinton's lie as to having sex with Monica thus was NOT a mortal sin for he intended no harm to Monica or anyone else} Murder and Manslaughter are mortal sins, but fornication is not).
Abortion prior to 1869 was a venial sin (Except in the last trimester when it rose to the level of a Mortal Sin). If you want to Read the whole Catholic rule prior to 1869 read Roe vs Wade. In Roe the US Supreme Court declared that the English Common Law rules as to Abortion were protected under the right to privacy under the US Consitution. The English Common law rule was based on the Catholic Rule as to Abortion that existed during the Middle ages and lasted as Catholic Doctrine till 1869.
In 1869 Pope Pius decided to change the doctrine to the present Doctrine that calls all abortions Murder (and as Murder a Mortal Sin under the Ten Commandments). Pius had just lost most of the Papal States to Italian Unification. He still had Rome but only do to the intervention of French Troops sent by Napoleon III (Which were withdraw once Prussia under Bismarck had defeated France in the Franco-Prussian War of 1871). Pius was also considered insane by many of his own Bishops but would stay as Pope till 1878 (He had been very progressive in his early years but by the time of the Italian Unification had gone not only reactionary but probally insane). His problem seems to be that he wanted to lead the reforms and unification of Italy on his and the Vatican's agenda NOT the agenda of the people or Italy. His change in the Doctrine has been viewed as an attack on the formation of the modern Italian state than a reform of church doctrine. He tried to strengthen the Church but failed for he opposed the national unity movements of the 19th Century but offered no positive alternative to it.
For informaion on Pius see:
http://www.newadvent.org/cathen/12134b.htm