Benjamin Banneker said this quote

Evil communication corrupts good manners. I hope to live to hear that good communication corrects bad manners.

~ Benjamin Banneker

The colour of the skin is in no way connected with strength of the mind or intellectual powers.

~ Benjamin Banneker

Standing at my door, I heard the discharge of a gun, and in four or five seconds of time, after the discharge, the small shot came rattling about me, one or two of which struck the house; which plainly demonstrates that the velocity of sound is greater than that of a cannon bullet.

~ Benjamin Banneker