Segregation was an useful tool in preserving the economic and social dominance of the white southerners. With segregation the African Americans were being discriminated against and kept in socially inferior position thus enabling the whites to get better paying jobs and generally better positions thus continuing the cycle of economical dominance of the white southerners.
They were signing a petition to establish the 'Columbia Territory'.
Their land was taken over, as was their food source, making it hard for them to survive. They did not have the same rights as Americans either until 1924. They were forced to live on reservations.
He would probably be proud of the fact that he is the country's first African American president and all the things he's done to help the country