Purdie is believed to have been born in Scotland by 1743; however, his exact birth date and exact place of birth are unknown. He was trained at an early age in the skills of printing in his motherland. His immigration to the American British colonies is not known for sure; however, by 1764 he took up residence in colonial Williamsburg, Virginia. At that time he was employed by the then current Williamsburg printer Joseph Royle, as an apprentice.