How many founding fathers were slave owners?

according to Michelle B. Bernard about 1/3 of those were slave owners including two of the three writers of the declaration, Thomas Jefferson who owned over 150 slaves, and ben Franklin who only owned 2 but those were house servants who he promptly let go and took up the task of abolitionism. Thomas Jefferson also freed his slaves at death but the financial situation of debt he left led to the acquisition of his estate so it is hard to say how many went free.