Who gives up their seats for Jem and scout at the courthouses?

In the packed courthouse, the children have trouble getting seats until Reverend Sykes helps them find seats upstairs in the balcony where the black people sit.

There, we went up a covered staircase and waited at the door. Reverend Sykes came puffing behind us, and steered us gently through the black people in the balcony. Four Negroes rose and gave us their front-row seats.

Reverend Skyes helps the kids find seats in the uppper balcony where the Negroes sit (Negroes is another word or name for a black person)