A as Criminal Label in the United States

From the Wolters Kluwer Bouvier Law Dictionary

“A brand for adultery.

A was the brand for those found guilty of adultery who were not executed. It is depicted
as a cloth letter A worn for life in Nathaniel Hawthorne’s novels, which is perhaps not historically accurate.

The punishment for adultery in colonial Massachusetts was death, or whipping followed by a requirement to wear an AD for a time.