Is.

Is. is a clerk's shortening of the given name Isaac. Busy writers cut common first names down to a few letters, often raising the last letters above the line, and the habit runs through deeds, wills, tax lists and census pages.

Is. is very short and easy to misread or skip. In place names the same letters can stand for Islands, so read a birthplace column with care. In a name column, look for a fuller spelling in another record to confirm Isaac.