biologist Charles Darwin. The goal of the "science" of eugenics was to improve the human race by eliminating what the movement's supporters considered hereditary disorders or flaws through selective breeding and social engineering. The eugenics movement proved popular in the United States, with Indiana enacting the nation's first eugenics-based sterilization law in 1907. In the following five decades, other states followed Indiana's example by implementing the eugenic laws. Wisconsin was the first state to enact legislation that required the medical certification of persons who applied for marriage licenses. The law that was enacted in 1913 generated attempts at similar legislation in other states. Anti-miscegenation laws, banning interracial marriage between whites and non-whites, had existed long before the emergence of eugenics. First enacted during the Colonial era when slavery had become essentially a racial caste, such laws were in effect in Virginia and in much of the United States until the 1960s. The first law banning all marriage between whites and Blacks was enacted in the colony of Virginia in 1691. This example was followed by Maryland (in 1692) and several of the other Thirteen Colonies. By 1913, 30 out of the then 48 states (including all Southern states) enforced such laws. The Pocahontas exception The Racial Integrity Act was subject to the Pocahontas Clause (or Pocahontas Exception), which allowed people with claims of less than 1/16 American Indian ancestry to still be considered white, despite the otherwise unyielding climate of one-drop rule politics. The exception regarding Native blood quantum was included as an amendment to the original Act in response to concerns of Virginia elites, including many of the First Families of Virginia, who had always claimed descent from Pocahontas with pride, but now worried that the new legislation would jeopardize their status. The exception stated: It shall thereafter be unlawful for any white person in this State to marry any save a white person, or a person with no other admixture of blood than white and American Indian. For the purpose of this act, the term "white person" shall apply only to the person who has no trace whatsoever of any blood other than Caucasian; but persons who have one-sixteenth or less of the blood of the American Indian and have no other non-Caucasic blood shall be deemed to be white persons". While definitions of "Indian", "colored" and variations of these were established and altered throughout the 18th and