When researching early records for our ancestors you MUST totally disregard spelling! Most of the spellings that we see in documents was done by court clerks or census takers; often our ancestors either didn't write or - if they did - had little interest in a precise way of spelling their own names or anything else.
I've been told that in very early documetns that writers would deliberately see how many different ways they could spell any given word! They were very much into phonetics in those days. Spelling just was not important until after ole Daniel Webster published his first dictionary in the early 1800s. Then spelling became a parlor game - and now we have the precise way that everything MUST be spelled.