City name, with an apostrophe at its end.

[Vocalcadence]

I am currently reading the memoir of William T. Sherman, the great Civil War General. In it, he consistently adds an apostrophe at the end of some North Carolina cities. ie: Goldsboro', Sneedsboro'. I have never encountered anything like this in any previous readings. Does anyone have a clue as to why he would do such a thing? General Grant does the same thing, in his letters to Sherman (the letters that Sherman includes in the memoir). I've researched this apostrophe usage extensively, to no avail. I'd appreciate any thoughts any of you might have, concerning this puzzle.