Primarily the letters of Frederick W. Gookin to his wife, Marie Sieboth Gookin, beginning with courtship letters and later detailing his daily activities during business trips or while Marie Gookin was away. Letters document Chicago friends, city activities, food, and weather, as well as details about his art world contacts during trips to New York. There are also letters from Marie S. Gookin to her sister Nathalie Kennedy, describing the family cats, vacations in Colorado, and a trip to Europe in 1914 during the outbreak of World War I.