Can someone explain who thurgood marshall was and how he was a hero pleae

Thurgood Marshall, because of his effort in stopping the discrimination against African Americans and beginning a major part of the civil rights movement. His most important achievement was winning a legal case when he was a lawyer in 1954. Brown vs. Board of Education would determine if schools would continued to be segregated or integrate. Thurgood Marshall is the reason that I, as an African American, can go to a school in the top 4% in the district. He was on the Supreme Court for 24 years and died on January 24 1992.