I know it has been awhile since your post, but just in case you are still looking, I have a lot of info on this William Perry Alexander's descendants.
Also, I am thinking maybe William Perry Alexander b. 1835 was from the group of Scots who arrived in the Cape Fear area from the highlands of Scotland between 1735 and 1775 and settled around what is now Fayetteville, NC. They might have migrated down through Moore Co., then Anson, Cabarrus and Mecklenburg following the War of 1812.
William Perry Alexander had a son named William Wallace (great Scot Hero) and Walter "Lafayette".Fayetteville was originally "Campbellton" which was established by the Campbell's of Argyl in the 1700's.It was renamed Fayetteville after the Marquis de Lafayette following the Revolutionary War.
If you would like the information that I have please email me at firstname.lastname@example.org and I will email the data back to you.There are 18 pages.
If anyone else is interested, please email a request to me.