Name the first lefthanded golfer to win one of the four major championships.

Bob Charles?

That's right, JoJo! Charles became the first lefty to win a major when he defeated Phil Rogers in a thirty six hole playoff in the 1963 British open. He shot rounds of 69 and 71 over the par 72 Royal Lytham and St. Anne's course to beat Rogers by eight strokes. By the way, Bob Charles is still playing tournament golf on the Senior PGA tour.