When Jacob Kieffer was born on 21 February 1802, in Somerset, Somerset, Pennsylvania, United States, his father, Jacob John Jacob Kieffer, was 42 and his mother, Eva Margaret Fritz, was 32. He married Rachel Kimerer in 1822, in Somerset, Pennsylvania, United States. They were the parents of at least 8 sons and 6 daughters. He lived in Green Township, Wayne, Ohio, United States for about 10 years and Chester Township, Wayne, Ohio, United States in 1860. He died on 5 March 1867, in Auglaize, Ohio, United States, at the age of 65.
German, Luxembourgish, and Jewish (Ashkenazic): variant of Kiefer . The surname Kieffer is also found in the province of Luxembourg and elsewhere in Wallonia (Belgium).