Harry Blackmun spent the summer of 1972 at his home in Rochester, Minnesota working in the library of the Mayo Clinic. This is where he did his medical research. A pregnancy was divided into three trimesters of three months each. During the third trimester, the fetus became viable, or capable of living on its own outside the womb. Abortions were considered safe during the first two trimesters. Powell, like Blackmun, also researched abortion during the summer. His in-laws were obstetricians so he could learn all of the stories from them.
At a conference vote in October, they voted six to three to allow abortion. Blackmun won the Chief's support by devising a formula where the state's interest in the abortion would begin in the second trimester, where they could be allowed.....
