The North (Joseph and Helen Oken) Family Papers (dated 1913-1990) include three generations of family correspondence spanning from the early 20th century to the 1990s. The bulk of the collection relates to Joseph and Helen North, but a significant portion also relates to Helen's family and includes correspondence of her father and mother Morris and Jennie Oken, and her sisters Lydia Oken Mates and Mary Oken Wilson. The collection largely consists of correspondence written between the 1930s and 1970s, and also includes family photographs, notes, and memorabilia.

Joseph and Helen North's papers document several major themes in their lives including their careers, political activism, economic struggles, and children. A small amount of correspondence relates to their time in Spain during the Spanish Civil War where Joseph worked as a foreign correspondent for the communist publication the New Masses and Helen worked in the medical service. Their papers also include materials related to Joseph's work as a journalist, both before and after Spain. Other materials inlcude correspondence from friends and family and materials related to their three children.

Correspondence between Helen and her sisters is exceptionally rich and provides an intimate look into their personal lives touching on a wide array of topics including their jobs, political beliefs, relationships, family planning and contraception, children, and care of their aging parents. They provide a unique view of how Communist Party members balanced their political activism and family obligation, and the ways in which family influenced political belief.

The papers of Morris and Jennie Oken also make up a small portion of this collection. Morris Oken was active in a number of labor and socialist organization in New York City, and his papers contain a large amount of material related to communism and political activism. The collection also contains a significant amount of materials related to Helen's sister Lydia and her husband Dave Mates. Lydia Oken Mates worked for many years as a Communist Party organizer in Detroit and Dave Mates was a Veteran of the Abraham Lincoln Brigades who was also involved in Communist Party activism throughout his life.

Other materials contained in this collection include clippings, flyers, and ephemera, a small number of negatives, and two artifacts: a hat taken from a Moroccan soldier who died in Spain, and a tsarist-era naval uniform cap from Russia.

Materials added to the collection in 2017 largely relate to Joseph North's writings and his work as a correspondent during the Spanish Civil War. They include press releases from the Spanish Republican Army's Ministry of National Defense as well as several reports and first-hand accounts from volunteers in the International Brigades. Also included among these materials is unpublished novel titled, I Come from America as well a folder of obituaries and articles paying tribute to Joseph North following his death in 1976.

Many of the correspondents in this collection are addressed by a variety of names throughout their correspondence. Helen and her family often address each other by their Russian names or variations of those names. In much of her correspondence Helen is often addressed as Vezl, Vezlenka, Honushinka, Annunshinka, or Anne. Joseph North, who was born Jacob Soifer, is also addressed as Jacob or Jake on many occasions, and in several instances his letters are addressed to Jacob Sofier. Helen's sister Lydia is often addressed as Lidushka, Liducinka, or Lilian, her sister Mary is addressed as Manya or Maninka; her father Morris is frequently referred to as Mitaya, and her mother Jennie, whose name is often spelled Jenny, is often referred to as Jenja.