Abortion wasn't always controversial. In fact, in colonial America it would have been considered a fairly common practice: a private decision made by women, and aided mostly by midwives. But in the mid-1800s, a small group of physicians set out to change that. Obstetrics was a new field, and they wanted it to be their domain—meaning, the domain of men and medicine. Led by a zealous young doctor named Horatio Storer, they launched a campaign to make abortion illegal in every state, spreading a potent cloud of moral righteousness and racial panic that one historian later called "the physicians' crusade." And so began the century of criminalization. In the first episode of a two-part series, we're telling the story of that century: how doctors put themselves at the center of legal battles over abortion, first to criminalize — and then to legalize.