Who is the First Major League Baseball umpire to use a chest protector?

The first Major League Baseball umpire to use a chest protector was Bill Klem. He introduced the device in the 1920s to enhance his safety while officiating games. Klem is noted for his significant contributions to the game and is often referred to as one of the greatest umpires in Baseball history. His innovative approach helped pave the way for modern umpiring equipment.