I assume that you are speaking of James Sample Alexander [you say Sample Alexander].
Both James Sample and Azariah Alexanders are sons of Josiah Alexander, who in turn is the son of Daniel Alexander, whose son is Hezekiah Alexander b. ca 1759.This Hezekiah m. Elizabeth (nee) Alexander.
They all go back to James B. Alexander, the weaver, perhaps s/o Rev. James and Mary (Maxwell) Alexander.
There are other Hezekiah Alexander's, like Hezekiah South Alexander.Mac.