SOLVED-1950's black & white drama

I was on another site and watched a 9min clip someone posted and frustratingly didn't have the decency to identify the film. I'm guessing it was filmed in the 50s-60s, in black and white, and dealt with racial tensions and it's effect within a black family.

The father works at a bank and was able to move the family into a middle-class white neighborhood. The scene includes the father, mother, teenaged son, and maternal grandmother.

The son, named Spence, returns home in the evening after getting expelled from school. Apparently he had a confrontation with a white female teacher where he talked back. Spence feels he took a principled stand whereas his mother and especially father want him to apologize.

He refuses defiantly and expresses his shame in his parents' position receiving a slap from his father. Throughout the confrontation his grandmother (off-screen) had been chiming in on his behalf. After the slap Spence is sent to his room.

The grandmother, in her frail condition, struggles downstairs to admonish her daughter and son-in-law. She makes them realize that Spence is only behaving in the way they raised him and it's them that are being cowards. They also hadn't been aware of how isolated Spence had been as the only black student.

Sorry for the length but I really would like to find this film.