Here are three key events that helped to end segregation in the US
1) Brown vs Board of Education (1954)- This Supreme Court case ruled that "separate but equal" schools for black and white students was a violation of the 14th amendment. This would help to end segregation in public schools, allowing for black and white students to attend the same schools.
2) Montgomery Bus Boycott (1955)- After Rosa Parks was physically removed and arrested for sitting in the whites only section of the bus, African American citizens of Montgomery refused to ride public buses until the seating policies were changed. In other words, African Americans wanted to be able to sit wherever they wanted to on the public bus. After one year, the city of Montgomery lost a significant amount of money since there were less people riding their buses. This resulted in the changing of their seating policy, allowing African American citizens to sit wherever they want.
3) Little Rock 9 (1957)- When 9 African American students wanted to attend the previously all white Central High School in Little Rock Arkansas, they were rejected. However, thanks to the US National Guard sent in by Eisenhower, these students were able to attend this school. This helped to end segregation in Arkansas schools.