I've been watching this board, hoping that you would post the information you obtained after visiting Petersburg. Your Frederick was a brother of my gg grandfather Christian (born Waldeck, Germany 1830). I know that after landing in NY (ship name?) in 1850 (maybe they came over together?) Christian moved to Menard Co (probably Petersburg as well) about 1852, married in 1857, and then moved to Lincoln, Logan Co in 1870. My family still owns the farm that Christian settled on in Lincoln and he was buried in that city along with his wife and children. Although I live in Michigan, I do travel to Lincoln several times every summer. After reading your posting, when I went to Lincoln in September I drove to Petersburg to see if any family was still there (hoping to find additional info). I did find the marker for Frederick at the Rose Hill Cemetery, discovered the Rothchild connection, found where they had two houses, and learned of their children: John, Will, Fred, Louisa (Hofing), Recca (Ritterbush), Pena (Kief), Anna (Weimer), Nettie (Miller) and one child who died in early childhood. But, alas, nothing on my side of the family. Were you able to unearth anything that might shed some light on Christian? Do you know if the whole family traveled from Germany together and/or if they all moved to Illinois? Would love to hear from you!