The Montgomery Bus Boycott was a year-long protest against racial segregation on public buses in Montgomery, Alabama. The boycott began on December 1, 1955, after Rosa Parks, an African American woman, was arrested for refusing to give up her seat to a white man.

Lyndon B. Johnson signed the Civil Rights Act of 1964 into law on July 2, 1964. The act outlawed discrimination based on race, color, religion, sex, or national origin in employment, public accommodations, and government programs.

The Cold War was a period of geopolitical tension between the United States and the Soviet Union and their respective allies. The Berlin Wall was built in 1961 to divide East and West Berlin. It was torn down in 1989, marking the end of the Cold War.

The Seneca Falls Convention was a women's rights convention held in Seneca Falls, New York, on July 19 and 20, 1848. It is often considered to be the beginning of the women's suffrage movement in the United States.

Woodrow Wilson signed the Nineteenth Amendment into law on August 26, 1920. The amendment granted women the right to vote.

The publication of Silent Spring by Rachel Carson in 1962 is often considered to be the beginning of the environmental movement. The book raised awareness of the dangers of pesticides and other pollutants to the environment.

Richard Nixon signed the Clean Air Act into law on December 31, 1970. The act set national air quality standards and created the Environmental Protection Agency (EPA).

The Stonewall Riots were a series of spontaneous demonstrations by members of the LGBTQ community in response to a police raid on the Stonewall Inn in New York City on June 28, 1969. The riots are often considered to be the beginning of the gay rights movement.

The Obergefell v. Hodges decision was a landmark Supreme Court ruling that legalized same-sex marriage in the United States. The decision was issued on June 26, 2015, by a 5-4 majority of the Court.

The death of Trayvon Martin, an unarmed black teenager, in 2012 sparked the Black Lives Matter movement. The movement is a decentralized network of activists and organizers working to end police brutality and systemic racism.

The Paris Agreement is an international agreement within the United Nations Framework Convention on Climate Change (UNFCCC) dealing with greenhouse-gas-emissions mitigation, adaptation, and finance starting in the year 2020. The agreement was negotiated by representatives of 196 state parties at the 21st Conference of the Parties of the UNFCCC in Paris and adopted by consensus on 12 December 2015.

The Harvey Weinstein scandal, in which dozens of women accused the Hollywood producer of sexual harassment and assault, is often considered to be the beginning of the #MeToo movement. The movement is a social movement against sexual harassment and assault.

The Time's Up movement is a social movement against sexual harassment and assault. It was founded in 2018 by a group of Hollywood actresses and activists.

The death of Trayvon Martin, an unarmed black teenager, in 2012 sparked the Black Lives Matter movement. The movement is a decentralized network of activists and organizers working to end police brutality and systemic racism.

The Paris Agreement is an international agreement within the United Nations Framework Convention on Climate Change (UNFCCC) dealing with greenhouse-gas-emissions mitigation, adaptation, and finance starting in the year 2020. The agreement was negotiated by representatives of 196 state parties at the 21st Conference of the Parties of the UNFCCC in Paris and adopted by consensus on 12 December 2015.