Parker was born in Baltimore, Maryland. His father was a construction equipment salesman. He is an honors graduate of the University of Maryland, College Park, with a major in history and a minor in art history. He continued his education at University of Maryland School of Law at the urban campus of the University of Maryland, Baltimore, graduating in 1973 with a Juris Doctor degree. He discovered wine as a student visiting Alsace, where Patricia, now his wife, was studying. For over ten years, he was assistant general counsel for the Farm Credit Banks of Baltimore; he resigned in March 1984 to focus on writing about wine.