Romer v. Evans, 517 U.S. 620 (1996), is a landmark United States Supreme Court case dealing with sexual orientation and state laws. It was the first Supreme Court case to address gay rights since Bowers v. Hardwick (1986), when the Court had held that laws criminalizing sodomy were constitutional.The Court ruled in a 63 decision that a state constitutional amendment in Colorado preventing protected status based upon homosexuality or bisexuality did not satisfy the Equal Protection Clause. The majority opinion in Romer stated that the amendment lacked "a rational relationship to legitimate state interests", and the dissent stated that the majority "evidently agrees that 'rational basis'the normal test for compliance with the Equal Protection Clauseis the governing standard". The state constitutional amendment failed rational basis review.The decision in Romer set the stage for Lawrence v. Texas (2003), where the Court overruled its decision in Bowers; for the Supreme Court ruling striking down Section 3 of the Defense of Marriage Act in United States v. Windsor (2013); and for the Court's ruling striking down state bans on same-sex marriage in Obergefell v. Hodges (2015). Justice Anthony Kennedy authored all four opinions, and was joined by Justices Ginsburg and Breyer in every one.

Lesbian, gay, bisexual and transgender (LGBT) rights in the United States have evolved significantly over time, however LGBT people in the USA may face legal challenges not experienced by non-LGBT residents. Until 1962, all 50 states criminalized same-sex sexual activity, but by 2003 all remaining laws against same-sex sexual activity had been invalidated. Beginning with Massachusetts in 2004, LGBT Americans had won the right to marry in all 50 states by 2015. Additionally, in many states and municipalities, LGBT Americans are explicitly protected from discrimination in employment, housing, and access to public accommodations.

Many LGBT Americans still continue to face legal and social challenges not experienced by non-LGBT residents, particularly in states with large conservative populations, such as in the Deep South, many parts of the Midwest, in rural areas, and in some Native American tribal nations.

Many LGBT rights in the United States have been established by the United States Supreme Court. In five landmark rulings between the years 1996 and 2020, the Supreme Court invalidated a state law banning protected class recognition based upon homosexuality, struck down sodomy laws nationwide, struck down Section 3 of the Defense of Marriage Act, made same-sex marriage legal nationwide, and prohibited employment discrimination against gay and transgender employees.

LGBT-related anti-discrimination law regarding housing and private and public services varies by state, leaving residents of some states unprotected. Twenty-three states plus Washington, D.C., Guam, and Puerto Rico outlaw discrimination based on sexual orientation, and twenty-two states plus Washington, D.C. outlaw discrimination based on gender identity or expression. The Equality Act, which is currently proposed in the United States Congress, would outlaw discrimination based on sexual orientation and gender identity nationwide.Family law also varies by state. Adoption of children by same-sex married couples is legal nationwide since June 2015 following the Supreme Court's decision in Obergefell v. Hodges (though Mississippi did not have its same-sex adoption ban struck down by a federal court until March 2016). Policies regarding adoption vary greatly between jurisdictions. Some states allow adoption by all couples, while others ban all unmarried couples from adoption.Hate crimes based on sexual orientation or gender identity are punishable by federal law under the Matthew Shepard and James Byrd, Jr. Hate Crimes Prevention Act of 2009, but many states lack state-level hate crime laws that cover sexual orientation and/or gender identity. LGBT people of color face the highest rates of discrimination and hate crimes, especially trans women of color.Civil rights for LGBT people in the United States are advocated by a variety of organizations at all levels and concentrations of political and legal life, including the Human Rights Campaign, Lambda Legal, GLBTQ Legal Advocates & Defenders (GLAD), American Civil Liberties Union (ACLU), the National Center for Transgender Equality, and the National Center for Lesbian Rights.