In 1933, when the Nazis rose to power, they cracked down on transgender medical research and clinical practice in the United States. Since 2021, Arkansas became the first U.S. state among now at least 21 other states banning gender-affirming care for minors. The 1930s eugenics and sexology collide In the 1920s, the new science of hormones was just reaching maturation and entering mainstream consciousness.