Time line: gay sex ed.

1904 In their push for sex ed in the classroom, Prince A. Morrow, a doctor, and G. Stanley Hall, a psychologist, warn against teaching about homosexuality.

1948 In response to the first Kinsey Report, the American Social Hygiene Association steps up efforts to idealize heterosexuality in sex-ed programs.

1964 The Sex Information and Education Council of the United States is formed, later affirming gay-positive sex ed for students.

1981 Congressional conservatives push through the Adolescent Family Life Act, which leads to a number of religion-based sex-ed programs that attack homosexuality.

1988 Congress passes the Helms Amendment, which forbids federal funding for AIDS education that "promotes or encourages" homosexuality.

1992 Oregon's Ballot Measure 9, which would have forbidden schools to "promote, encourage, or facilitate homosexuality," fails.

2000 The Henry J. Kaiser Family Foundation reports that 76% of U.S. parents want their children to learn about sexual orientation in school.

2004 California passes a gay-inclusive law stating that sex education must be medically accurate and age-appropriate.