The Supreme Court hands down decisions every year, but not every one makes history. Here are four landmark cases to know:

1. Brown v. Board of Education (1954)

This decision ended segregation in public schools. Prior to this decision, "separate but equal" had been the law of the land. Meaning, segregation was legal as long as the education institutions were on equal footing. However, in Brown v. Board, the Supreme Court overturned its past precedent in saying, "Separate educational facilities are inherently unequal." Now, segregation of schools by race is unconstitutional.

2. Loving v. Virginia (1967)

Until this case made it to the Supreme Court, interracial marriage wasn't a constitutionally protected right. By 1967, more than 30 states had legalized marriages between different races — but it was still illegal in 16 states. The Court ruled in Loving v. Virginia that Americans have the fundamental right to marry anyone of any race under the U.S. Constitution.

3. Roe v. Wade (1973)

This decision is famous for legalizing abortion across the United States. Roe v. Wadestates that the right to privacy (under the Due Process Clause of the Fourteenth Amendment) allows women the right to choose whether or not to continue a pregnancy. However, this protection only extends through the first trimester of pregnancy. The Supreme Court issued another ruling on abortion laws this year in Whole Woman's Health v. Hellerstedt.

4. Obergefell v. Hodges (2015)

The opinion in this case was issued just last year and it legalized same-sex marriage across the country. Just as in Loving, the Supreme Court decided in Obergefell that Americans have a fundamental right to marry whomever they choose — regardless of sex. At the time of this decision, 13 states still had not legalized same-sex marriage.