What is the difference between sick and exhausted?

The difference between being sick and feeling exhausted is that when you're sick, there's a virus involved which causes a disease and makes you ill.

Feeling exhausted on the other hand is slightly different. You feel physically or mentally drained due to overworking, stress and exercising. 

When you're sick, you're ill, or not feeling well.

When you're exhausted, you're tired, or worn out.

It reinforce the idea that the rights given to others are not extended to African Americans.

* Hope this helps :)