"Had Blackmun’s draft opinion been adopted, it would have left states free to prohibit abortions for nonmedical reasons. However, Blackmun reluctantly joined Burger in seeking a delay, and the majority voted to put off a decision on the abortion cases until the fall. Blackmun spent the summer working in the Mayo Clinic’s library in Minnesota. He researched the history of abortion in Persian, Greek and Roman times. He also studied abortion laws adopted in 19th century America and concluded that the bans were driven not by moral imperatives but by the reality that, before antibiotics, abortion -- like other medical procedures -- was dangerous. When Blackmun returned to Washington, he had a long draft. It was a thorough work of medical history, but short on constitutional law. It also was hazy on just when abortion would be permitted or prohibited."