Arthur, William (1857) An Etymological Dictionary of Family and Christian Names. New York: Sheldon, Blakeman. Public Domain.
WHITMAN
As described in historical dictionaries
An Etymological Dictionary of Family and Christian Names (1857)
From wight, in old English, lively, quick, and man, or from the Dutch, wight, weighty, ponderous, Wightman, a stout man, or it may be, after all, simply White-man.
Origin: English
Region of origin: British Isles
Country of origin: England
Religion of origin: Christian
Language of origin: English