New Thatcher Information

For years I've been stuck on the parents of my great-grandfather Alexander M. Thatcher. It appears he was born in 1818 in Chester County, Pennsylvania. I've been researching for 24 years. Today I've finally found something useful on Ancestry. It's a census of Chester County in 1779 listing all the Thatcher men. It also has wills of Thatcher men in Pennsylvania. I'm sure not all the men had wills. I can use this information to research these men to see what sons they may have had in the county later on, who would be potential fathers or grandfathers of Alexander Thatcher. I wonder what I will find.