I am not a Jagger, but my grandfather, George Lewis (or Louis) Haas (born near Columbus Grove, Ohio in March 1875) said Dean Jagger was a first cousin. He had never met Jagger, but he claimed to know "over 100" of his first cousins! I do not know on which side of his family the Jaggers were, but a clue would be the name Haas, as well as his mother's maiden name Altstaetter. She was one of a dozen children of Jacob Altstaetter, who came to the US around 1832 and had at least 12 children who survived, which explains his many first cousins.