Just wanted to note that the name Ferris is found in written records in a vast variety of forms.
When searching census records or other such data, you will need to be aware of name spellings. In some cases, it is impossible to determine what spelling the individual used during their life. I try to use the spelling on their gravestone if I can locate it, because the people who erect the stone probably know best what the correct spelling was.
Some of our ancestors were illiterate, accounting for the spelling issues. Others made a concerted attempt to differentiate themselves. I suspect that is why the Quaker / Zachariah Ferris lineage went to using the double “s”, Ferriss, in so many cases.