As long as the matador does not harm or kill the bull, bullfighting is legal in the United States.
Detroit is one city that has featured bloodless bullfighting, bringing in some of the best Spanish and Mexican bullfighters to demonstrate their skills, speed, and courage without doing overt harm to the animals.
In Portugal it is illegal to kill a bull in the arena, so it is removed and slaughtered in the pens as fighting bulls can only be used once.
Bullfighting has its origins in prehistoric bull worship and sacrifice, and the killing of the sacred bull was commemorated in the mithraeum wherever Roman soldiers were stationed.