Brian, As most people will attest, Green Castle is pretty small. Most of the research would be done in Milan at the Sullivan County Library, Courthouse and Historical Museum. There may also be some items in Unionville at the Putnam County Library and on into Kirksville (Adair County). There is a pretty strong oral history amongst the "natives" so I would ask away on here. My dad grew up in that area..actually Pennville and Green City. Not sure how much I can help. What names are you looking for? Marsha Sears Researching: SEARS, PICKERING, PITTMAN, MCCUNE, MCDOWELL, RODGERS, YARDLEY, DEEDS, NEWMAN, NEEDHAM, and many others.