Of the Little Rock Nine, only three graduated from Central High School. These three were:
- Ernest Green. He went on to college at Michigan State University and held several high positions in government.
- Carlotta Walls (now LaNier) she too went on to Michigan State and later graduated from what is now Northern Colorado. She is on their Board of Regents
- Jefferson Thomas. He did not finish college but later became a minister and a businessman. He also served in the army.
I'm not sure how you'd count this, but Theresa Mothershed got a diploma from Central after taking correspondence courses and going to summer school in St. Louis.
Please follow the link for information on these three and the others. I should note that all of them finished high school somewhere (though one got a GED) and most graduated from college.
The Little Rock Nine entered Central High School in September of 1957 in an attempt to integrate the school after the landmark 1954 Brown v. Board of Education Supreme Court case. Arkansas National Guard troops called by Governor Orval Faubus prevented the students from entering the school on its opening day, and they were not able to enter the school until late September, when President Eisenhower called in the 101st Airborne Division of the U.S. Army to protect the students. Later, the 101st Airborne was withdrawn, and Eisenhower federalized the Arkansas National Guard so that they could continue to protect the students. However, the students in the Little Rock Nine were continually harassed by white students. Minnijean Brown was expelled from the school for speaking and acting against students who were harassing her, and she later graduated from a high school in New York City.
At the end of the year, senior Ernest Green became the first and only of the Little Rock Nine to graduate from Central High School in a ceremony attended by Martin Luther King, Jr. During the next school year, the voters chose to shut down all the high schools in Little Rock rather than to integrate them, so all the other students graduated from other high schools or via correspondence classes. An excellent source of information is the memoir written by Melba Pattillo Beals, one of the Little Rock Nine, called Warriors Don't Cry.