The KKK (Ku Klux Klan) was founded in 1866 and soon spread throughout the South. Their goal was to bring back white-supremacy and often turned to violence in order to scare and punish black and white protesters.
In shared public places, such as the theatre, the black and white people would be separated within. This shows that they had to go to the 'Colored Balcony' which is likely to have been very poor in comparison to the one for the whites.
In the South, following the Civil War, racial segregation was introduced in order to discriminate against black people. Jim Crow laws were passed and blacks and whites would use separate public spaces. Blacks were sometimes compared to animals such as dogs.