I also am from Southeast Missouri and have gggggrandparents that were Pfefferkorns. The first being Pierre Pfefferkorn b.1730 in Alsace France. My gggrandfather, Joseph Pobst married Mary Magdalena Pfefferkorn in 1824 in France. She moved the Pobst family to New Hamburg, after Joseph most likely dying in Ky on the trip down. She settled in New Hamburg and was the first of my family members to immigrate. She died in 1865 in Missouri