Abraham Louderback's brother was my gggg grandfather, Daniel. I too believe David was their father. Your Abraham came to IL about 1824 and my Daniel followed a little later after a stay in and around Franklin Co., IN. Daniel's son Richard married in IN before they all came to IL.Richard and MaryAnn Howk had a son George Louderback who married Sarah Crockett in Brown Co., IL.They were the parents of my grandmother, Rebecca Louderback Cameron. Most of the Louderbacks lived in Adams, Schuyler and Brown Co, IL and eventually settled in and around Camp Point, Adams Co., IL.Sounds like we are distant cousins.