Stephen Martindale V was born 11 October 1893. After graduation from La Crosse High School he attended Hamilton College. His senior year was spent at the University of Michigan, Ann Arbor, but discontinued in order to enlist in the Ambulance Corps during World War I. After the war he worked for the American Relief Administration and traveled in Europe and Russia. Stephen returned briefly to La Crosse after his father's death to help settle the estate (see Stephen M. IV, Business Papers, Estate). In 1924 he had his own business called “On-a-Door Shoe Shelf Company” in New York City. This was liquidated in 1926, and Stephen worked for a liquor importing company in New York City and Chicago in the 1930s and 1940s. Around 1945 he moved back to La Crosse to join Katharine in the family business, but he encountered financial and other difficulties.

Stephen was married at least twice, first to Joan Buckminster on 2 September 1918. This marriage ended after a few years, either by divorce or Joan's death. There is a 1924 Benson, Vermont land deed which names a Pauline K. Martindale as the wife of Stephen V, but there are no other references to her. He later married Margaret Miller with whom he had two children, Margot born in May 1930 and Stephen III born 10 September 1937. Stephen V died, apparently a suicide, in La Crosse on 8 July 1949.

Stephen V's papers are mostly correspondence. The largest group of letters, those from Stephen to his parents and sisters, provide information about his youth, college years, personal life, work for the American Relief Administration, business activities, and family relationships. Correspondence with Friends, Relatives, and Associates and Postcards both include correspondence to and from Stephen. The former includes a few early letters to his Aunt, Anna Martindale, and miscellaneous business correspondence. The 1924 Benson, Vermont, land deed mentioned above is filed here.

The folders for Stephen's wives and children contain correspondence from each of them to Katharine and Sophie Martindale and concern mundane family matters. Later correspondence reflects Katharine's attempts to maintain family ties and to give away furniture, antiques, and other items from the family home.