Origin of ma'am
Examples from the Web for ma'am
“Good morning, ma-am,” he said, halting at a respectful distance.The Golden Shoemaker|J. W. Keyworth
also maam, 1660s, colloquial shortening of madam (q.v.). Formerly the ordinary respectful form of address to a married woman; later restricted to the queen and royal princesses or used by servants to their mistresses.