What problem was raised by Smith and Carlos of USA?

What problem was raised by Smith and Carlos of USA? With what gesture did they bring international attention to the social problems in USA?

Answer:
Receiving their gold and bronze medals, respectively; the American athletes wore black socks and no shoes to represent Black poverty. With this gesture, they tried to draw international attention to the prevailing racial discrimination in the United States. The black-gloved and raised clenched fists were meant to symbolise Black Power.