John Mc/MacLennan from Isle of Skye Inverness-shire to PA

My maternal grandmother's name was McClenin, but I have seen various spellings. On a trip to Scotland last year, I learned that her ancestors' name was probably MacLennan. While there, I also found a record of a John McLennan (b.1743 on the Isle of Skye) who immigrated to Philadelphia in 1775. I know my McClenin family was in PA in the very early 1800's, but I don't know where. If you have any information that might close this gap, I would love to hear from you. Family names were John, William and Thomas.