The Mary Haynes Lane papers include correspondence, writings, memorabilia, biographical information, and photographs dating from 1861-1922. Of particular note are letters that she wrote as a student at Mount Holyoke Female Seminary from 1861-1863. These letters are written to her brothers, Charles T. and John Haynes. Lane discusses many aspects of her life at the Seminary, including the rules, her course work in botany, domestic work on campus, and prayer meetings. These letters also include references to the Civil War and its impact on students. Also included in the papers are two essays by Lane written in 1889 and 1907 which discuss the history of Mount Holyoke and her experiences as a student. Biographical material includes notes and obituaries concerning Lane. Included in the memorabilia is a United States Christian Commission pin worn by her husband, John William Lane, during the Civil War and letters by Charles T. Haynes. The photographs consist of two formal portraits of her taken in 1868.

This collection is organized into five series:

• Correspondence
• Writings
• Memorabilia
• Biographical Information
• Photographs