The new version also allowed white people to have up to one-sixteenth "Indian blood." Finally, the burden of proof regarding the veracity of a person's racial certificate was placed not on the state but on the individual. Shields, determined that Connor was white but that Johns, in addition to being part white, was also part Indian and African American.

The Senate passed the modified bill on February 27 by a vote of 23 to 4. Byrd Sr., and twelve other senators abstained.) After voting down the earlier version on February 21, the House followed the Senate's lead, approving the bill on March 8 by a vote of 72 to 9. Lee Trinkle signed the Racial Integrity Act into law on March 20.. Citing the Racial Integrity Act, he refused to issue a license and Johns immediately sued in the Circuit Court of Rockbridge County.

Testifying before Judge , and Silas Coleman, a resident of Amherst County, provided anecdotal corroboration.

(Eugenics was later widely discredited as pseudoscience.)In part in order to accomplish this separation of races, the state found it necessary to keep track of who was white, black, and Indian.

From 1853 until 1896, Virginia required that all births and marriages be recorded, and that the race of all parties be noted.

In 1785, that : a mulatto was anyone with one-fourth or more "negro blood." In 1860, the definition stayed the same.

Six years later, however, "mulatto" was replaced by the word "colored," and Indians were now defined as being not colored and having one-fourth or more "Indian blood." That definition remained the same in 18.

Although nonmarital relationships were commonplace, interracial marriages that legally recognized any such relationship had been prohibited in Virginia since 1691, and declared "absolutely void" since 1849; still, whites, blacks, and Indians in Virginia sometimes married.

According to federal census reports, between 18 the number of mixed-race Virginians (or "mulattoes," as they were referred to in the census) increased from 122,441 to 222,910.

Indeed, Plecker admitted to applying a standard beyond the law when identifying people as African American.

Whereas the General Assembly had defined "colored" in 1910 as someone with one-sixteenth or more "negro blood," Plecker defined it as someone "with even a trace of negro blood on either side." This included nearly all Virginia Indians, according to Plecker, because they had so thoroughly interbred with African Americans.

The Racial Integrity Act went a step further and attempted a first for Virginia: defining a white person.

According to the proposed law, to be white a person must have "no trace whatsoever of any blood other than Caucasian"—in other words, the standard already being applied by Walter Plecker.

Helping to fuel these concerns was the eugenics movement, which was based on the idea that humans can be selectively bred in similar ways to plants and animals.