Beginning in the second half of the 19th century , American rates of sexually transmitted diseases skyrocketed . Causes cited by historians include effects of the American Civil War , and the ignorance of prevention methods promoted by the Comstock laws . To fight the growing epidemic , sex education classes was introduced to public schools for the first time , teaching about venereal diseases and how they was transmitted . They generally taught that abstinence was the only way to avoid sexually transmitted diseases . Condoms was not promoted for disease prevention because the medical community and moral watchdogs considered STDs to be punishment for sexual misbehavior . The stigma against victims of these diseases was so great that many hospitals refused to treat people who had syphilis .