he was born in pittsburgh to joseph richardson dilworth and annie hunter (wood) dilworth. he enlisted in the marine corps in world war i and was commissioned as an officer in world war ii. in 1938, he joined the law firm of dilworth paxson. in 1921 he graduated from yale university, where he was a member of scroll and key and delta kappa epsilon, and lettered for the varsity football team. in 1926 he graduated from yale law school, afterwards becoming an attorney in philadelphia. on august 6, 1935, he married ann elizabeth kaufman. they had a daughter, deborah, and a son, richardson jr.