The History of Premarital Blood Tests

If you are of a certain age, you remember when people had to undergo a blood test in order to get a marriage license. In my elementary school, kids who "knew" told us that it was to uncover possible Rh factor incompatibility, which was a thing at the time. Today, young people tell each other that it was a genetic test to make sure the bride and groom were not related to each other, which is demonstrably wrong, because DNA tests just weren't available back then. Eventually we all learned on our own that it was a test for syphilis, a part of a nationwide battle against the disease launched by U.S. Surgeon General Thomas Parran Jr. in the 1930s.
States took up the challenge with tests for people getting married until the majority of states required them. Some states later tested for other diseases, but then gradually dropped the requirement until the last premarital blood test was dropped ...in 2019. Read about Parran's crusade and the results of these required tests at Mental Floss.