Jefferson Douglas Moeckly was the third child born to Johannes Ulrich Möckli and Frederica (Huglin) Moeckly. Jefferson was born on the farm near Crocker, Iowa in 1862 and died on 31 March 1939. He married Lydia Sexauer (1870-1955) about 1894. They had two children, Theodore Moeckly (1895-1959) and Fletcher Moeckly (1903-1978). Jefferson is shown on the right next to his older brother Jacob (Jake) Moeckly.