Complex sentence: Mamie Julia Rearden (born September 7,1898) is an American supercentenarian who at the age of, is currently the world's 7th oldest living person, and the oldest black person in the world.
Split into simpler sentences: Mamie Julia Rearden (born September 7,1898) is an American supercentenarian. She is currently the world's 7th oldest living person and the oldest black person in the world.