Mary Ware Dennett, an activist in the US for birth control and sex education in the early twentieth century, wrote an educational pamphlet in 1915 called “The Sex Side of Life, and it was published in 1919. The pamphlet defined the functions of the sex organs, emphasized the role of love and pleasure in sex, and described other sexual processes of the body not usually discussed openly. In the early twentieth century in the US, individuals did not have wide access to sex education due to the limitations enforced by the Comstock Act, which prohibited the distribution and discussion of topics that were considered obscene. In 1929, the US tried Dennett for mailing her pamphlet as a violation of the Comstock Act, sending obscene material through the United States Postal Service. Dennett’s pamphlet, Tthe “Sex Side of Life,” and her subsequent trial, United States v. Dennett, contributed to a national discussion about sex education and human reproduction and led to the revision of reproduction- related obscenity laws.

Hideyo Noguchi researched bacteria, including Treponema pallidum, the bacterium that causes syphilis, in Japan and the US during the early 1900s. Syphilis is a bacterial infection that spreads primarily through sexual transmission and can cause symptoms such as rashes, genital sores, and even organ damage. Noguchi recognized that Treponema pallidum causes neurosyphilis, which is when the syphilis infection spreads to the covering of the brain, the brain itself, or the spinal cord. Before Noguchi’s work, researchers knew about Treponema pallidum and the symptoms of the disease but did not know that untreated syphilis could lead to neurosyphilis. Additionally, Noguchi worked to alter and improve methods to diagnose syphilis. Noguchi’s work helped future researchers and doctors better diagnose people with syphilis, assisted them in understanding how to treat the disease’s long-term side effects, and helped them reduce the spread of syphilis, including between pregnant people and their fetuses.