Prince Hall was an 18th century black man in the colonies who was indoctrinated into a British lodge, I believe. He later founded a lodge of his own in the colonies. For awhile, his lodge was one of the few, if not the only one, open to black men. Today, from what I understand, there are more black Masons in the standard lodges than in Prince Hall, which I believe still exists. I don't think Prince Hall masonry is considered irregular although it might be.