2.75” oval with metal back and bar pin. Front has couple of scattered age marks primarily on the rim edge. Text reads “World’s Heavyweight Championship/Convention Center/Clay vs. Patterson/Las Vegas, Nov. 22-‘65/Press.” This historic button is for a fight with Ali as champion and Patterson attempting to be the first to win the World Heavyweight title three times. Although he was using the name Muhammad Ali at the time he is referred to as “Clay” on this button. Ali called Patterson an “Uncle Tom” because Patterson refused to call him by his adopted name. Rather than a quick knockout, Ali humiliated and punished Patterson for twelve rounds before winning by a technical knockout at the end of the twelfth. See next related item. Rare.