Here are subject terms to consider. Other options may include using specific names (e.g., Daisy Bates, etc.)
Central High School (Little Rock, Ark) – History – 20th century
School integration – Arkansas – Little Rock – History – 20th century
African Americans – Civil rights – Arkansas – Little Rock – History 20th century
African American students – Arkansas - Little Rock – History – 20th century
Little Rock (Ark) – Race relations
Over the course of history, terminology has changed, even in the less than 60 years since the Little Rock Crisis. Keep in mind that materials created at the time of the event will use different words to imply race. Locating possible historic synonyms can be done by searching the current term in the the Oxford English Dictionary.