Dr. John Rock and Gregory Pincus, both educators from Harvard, researched methods to use the hormone progesterone as a means of birth control. By 1954, the pair had produced the Pill regimen as it is seen today: 21 doses, followed by 7 days where women should not take the Pill.
Despite its success, both Pincus and Dr. Rock avoided calling it a birth control pill, and it was not publicly recognized as such until 1955. Many people opposed birth control methods because they thought they would lead to sexual promiscuity.
In 1957 the FDA approved the Pill for prescription to women suffering from severe menstrual disorders. Over the next two years, the number of women suffering from these disorders increasesd dramatically, totally more than 500,000 by late 1959. After an expansive field trial, the FDA approved the sale of the Pill for the purpose of birth control.