Not sure exactly how but you're probably a relative of mine. My grandfather was born in Pottstown (Walter Carroll Yerger) in 1922. His father (Clinton Irvin Yerger) was born in Pottstown in 1900. William is not a listed name of a sibling in the records I can look at right now. Perhaps he was a cousin or uncle or nephew or something but living in Pottstown at the exact same time with the same last name...I'd say good chance they're related.