We’ve had several notably incredibly wealthy first families (Washington, Kennedy, both Roosevelts, Hoover, LBJ, among others) but, if he somehow beats Bush, would John Kerry and Teresa Heinz Kerry be the richest yet relative to their era? If not, who was? Her net worth is somewhere around $500M (even though he can’t touch it without her permission thanks to their pre-nup). H. Ross Perot is worth significantly more than that but, thankfully, we never elected him. And Vice President Nelson Rockefeller doesn’t qualify.
Probably not relatively speaking.
There’s a list floating around about the 100 Wealthiest in U.S. history, based on worth as a percentage of the gross national product. Washington made the list, but IIRC none of the others on your list did.