Who was the person who believed that African-Americans should form a separate society by appealing to African Americans with message of black pride?

Marcus Garvey

Explanation:

Marcus Garvey and his organization, the Universal Negro Improvement Association (UNIA), represent the largest mass movement in African-American history. Proclaiming a black nationalist "Back to Africa" message, Garvey and the UNIA established 700 branches in thirty-eight states by the early 1920s.