Rick, I think you mean Abraham and Elizabeth were married about 1818. So they would be born about 1797. I think the clue might be their birthplaces which you neglected to give. 1841 will only say if born in county, so you should use data from 1851 & 1861. You should also list out their birth years as derived from census ages. Remember 1841 is rounded, so use 1851 & 1861 and check for consistency. Check also for people who might be living with them or nearby. Often you might find relatives next door. Peter