Sorry that it has taken so long to reply to your message. I don't really know why my Bear's changed the spelling to Bair. They appear on the 1850 and 1860 PA Census for Westmoreland County as Bear. Then, some of the children appear as Bair on the 1870 PA Census and in other documents. I'm not sure if the children were trying to distinguish themselves from the earlier generations or from other Bear families in the area. Any ideas that you have would be appreciated!