Son William's marriage record lists his (William's) father's name as "Fred."
Apparently it is the custom in Germany to give several names. These are not necessarily seen as "first" and "middle" names, but rather a series of names. One web site even suggests that the name given at baptism is often commonly adopted as the "first" name. Frederick's baptism records records him as "David Freiedrich Schweikert" however his son William listed his father's name as "Fred" on his (William's) marriage certificate. I have hence labled him as "Friedrich David Schweikert." (ead)