I have also heard of Pleckart as being married to a Lint. The reason we decided on Blackhart is that name is in the census at the time period in question. A similiar sounding letter may have been the confusion. Much the same is true when the d and t are sounded in German when it is spoken. Sophia was born in Somerset,PA April 15,1820, married Peter A. Hay(s) Aug. 17, 1837, resided in Mt. Pleasant, Westmoreland Co. and died July 20, 1899. Her tombstone is in Tarr's Cemetery. She had 14 children so I have been trying to find out where their offspring may have ended up. Thanks for your reply.