Social injustice refers to unjust actions in society. This occurs when the unequal get treated equally while equals get treated unequally. Homophobia, ageism, and discrimination are three common social injustice examples. 

In an ideal world, all people of different genders, races, origins, and religions would be treated in the same way, in all aspects of life, including, but not limited to, healthcare, education, housing, work, etc. In the past, there have been great efforts and movements to improve conditions for women, African Americans, and the LGBTQ+ community, as listed below:

The women's suffrage movement lasted decades and included the fight to gain voting rights among women within the United States. The movement began around the mid 1800s and ended in August 1920 when the ratification of the 19th amendment occurred. Several generations of woman suffrage supporters lectured, wrote, marched, lobbied, and practiced civil disobedience to achieve revolutionary change and guarantee women the right to vote. Other tactics included picketing, silent vigils, and hunger strikes. The movement not just included women, but also women of color and men who believed in the right to vote no matter the gender. The suffrage movement was a time where societal and political changes occurred as a result of the refusal to comply with such discrimination anymore. 

Women's Right to Vote
Passed by Congress June 4, 1919. Ratified August 18, 1920

"The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of sex."

The Stonewall riots (or Stonewall uprising/rebellion) were a response to a police raid that occurred in the early morning hours of June 28, 1969, at the Stonewall Inn in the Greenwich Village neighborhood of New York City, New York, and took the form of  spontaneous demonstrations by members of the gay community. When the police became violent, patrons of the Stonewall along with other lesbian and gay bars, and neighborhood street people fought back. The Stonewall riots induced a time of exponential change in the transformation of the gay liberation movement and the twentieth-century fight for LGBT rights in the United States, with activist groups being formed along with newspapers created to promote rights for gay men and lesbians.

“Borrowing tactics from the civil rights and women’s rights movements the struggle for gay liberation was organizing across the country in powerful ways. People began creating organizations and making their voices heard. Progress was happening: Minneapolis had already passed a human rights ordinance that protected LGBT people— yes, it specifically included gender identity in 1975. Then in 1993 Minnesota became the first state in the country to pass a human rights act that included protections for transgender people.” 
- Jenkins, Andrea. “Power to the People: The Stonewall Revolution.” QED: A Journal in GLBTQ Worldmaking, vol. 6, no. 2, Summer 2019, pp. 63–68. EBSCOhost, doi:10.14321/qed.6.2.0063.

A year after the stonewall riots, the first gay pride marches took place in Chicago, Los Angeles, New York and San Francisco. Within a few years, gay rights organizations were founded across the world, and today, LGBTQ+ Pride events are held annually in June in honor of the Stonewall riots. Gay marriage in the U.S. started to be legal in 2004, with legislation passed in Massachusetts, and then was fully legal in 2015 with a supreme court ruling. Through cohort and period effect, America went through a generational change regarding the topic of gay marriage, influencing this critical ruling for the LGBTQ+ community (Hart-Brinson). The court stated:

“The Constitution promises liberty to all within its reach, a liberty that includes certain specific rights that allow persons, within a lawful realm, to define and express their identity." https://www.supremecourt.gov/opinions/14pdf/14-556_3204.pdf