The papers of Clara Barton (1821-1912) span the years 1805 to 1958, with the bulk of the material dated 1861-1912. The collection includes the personal papers of Clara Barton and official records of the American National Red Cross (formerly the American Association of the Red Cross) retained by Barton during her tenure as president from 1881 to 1904. The records of the American Red Cross are contained principally in a series of Letterbooks and in a Red Cross File. Since Barton's life was so closely linked to the organization's development and operation, however, some mingling of material exists, and records relating to Red Cross activities can be found throughout the collection.

Barton's diaries and journals provide insight into her private views and reflections, whereas material in the Subject File, Family Papers, and General Correspondence series relates to her interest in women's rights and other reform issues. A Speeches and Writings File contains lecture notes, drafts, and proofs not only of her own lectures and writings but also those of others. Barton's career as a humanitarian and relief organizer is further documented, mostly through contemporary newspaper accounts, in a series of scrapbooks. Decorations and medallions bestowed upon Barton by foreign governments and by public and private organizations are included in a Miscellany series.

Few items are included for the period prior to 1861. Sporadic diary entries cast light on these early years, as do letters in the Family Papers from members of Barton's immediate family and from Martha Elvira Stone and Bernard B. Vassall. Letters to Barton from Lucien Burleigh, a school instructor from Barton's formative years, are contained in the General Correspondence series.

While providing relief services on battlefields during the Civil War and while in Europe during the Franco-Prussian War, Clara Barton found time to keep her diary and to make notes from which she later prepared lectures. Some of the diaries are supplemented by copies of letters, addresses, and expense accounts incorporated in the diaries. Diaries kept by various associates and members of the Red Cross staff who frequently mentioned Barton are also included in the Diaries and Journals series.

At the close of the Civil War, Barton helped organize the Office of Correspondence with Friends of the Missing Men of the U.S. Army to locate and identify Union soldiers whose fate or whereabouts was unknown. In the four years of its existence the office provided information to more than twenty-two thousand families, identified most of the graves in Georgia's Andersonville prison, and, in the process established a National Cemetery there. Papers relating to this organization and to the Andersonville prison are included with Civil War records in the Subject File, as are letters of Dorence Atwater, a former prisoner at Andersonville who aided Barton in her mission to identify those who had died in the prison. It was during this time that Barton and Atwater, embarked on a speaking tour to appeal for information concerning the missing men and to defray the expense of the undertaking. Material relating to the tour, including drafts and notes of the lectures, is contained in the Speeches and Writings File.

Clara Barton suffered from periodic nervous breakdowns and in 1869 was ordered by her doctors to recuperate in Europe. There she met Louis Appia, a member of the International Committee of the Red Cross, who introduced her to the Red Cross movement. In her first cooperative effort with the Red Cross, Barton organized and managed relief activities for civilians during the Franco-Prussian War. The Subject File contains information on this effort.

Following her activities in Europe, Barton was called upon to promote the passage of the Geneva Convention in the United States Congress and to organize the American Red Cross. The Red Cross File that she accumulated over the years forms the largest series in the collection and is divided into two subseries, the International Committee of the Red Cross and the American National Red Cross. The former includes files for several International Red Cross conferences which Barton attended as a delegate, while the latter contains material indicating that the American Red Cross was not only founded by Barton but was also sustained by her for many years. Her control over the operations of the American Red Cross dates from its inception in May 1881 until her retirement in June 1904, except for a few months in 1883 when she acted as superintendent of the Women's Reformatory Prison at Sherborn, Massachusetts.

The records of the American National Red Cross relate to the organization's foundation and administration, including actions taken to protect the Red Cross insignia, the development and scandal of Red Cross Park, and the final congressional investigation into Barton's stewardship. The bulk of the material, however, relates chiefly to the Red Cross's response to appeals for aid from the victims of natural disasters and war.

The Letterbooks series contains outgoing letters from the Red Cross for the period 1882-1904. Included are letters signed by Barton as president, as well as those by Julian B. Hubbell, Barton's associate and chief field agent of the Red Cross, and by other Red Cross officials such as her nephew Stephen E. Barton and George H. Pullman. The volumes include letters sent to the International Committee at Geneva and to local Red Cross chapters in the United States, letters and narrative reports from various disaster relief operations, and records of camp service in the states during the Spanish-American War. Copies of some of Barton's personal outgoing letters are also present. A number of the letterpress copies are almost completely illegible.

The General Correspondence series contains letters exchanged between Barton and her friends and associates. In addition to documenting her relief work, the correspondence also reveals Barton's interest in other progressive movements of the period, as demonstrated in letters from Mary Weeks Burnett and Frances E. and Mary Willard on temperance matters and from Susan B. Anthony, Lucy Hall Brown, Mary Seymour Howell, Harriet Taylor Upton, and Charlotte Fowler Wells concerning woman suffrage. Many of the correspondents in the General Correspondence series are also represented in the Subject File.

Among principal correspondents in the papers not previously mentioned are Alvey A. Adee, Louis Appia, Harriet N. Austin, E. Florence Barker, William E. Barton, Henry W. Bellows, Mabel T. Boardman, Samuel W. Briggs, Benjamin F. Butler, Jean Henri Dunant, Edmund Dwight, Frances D. Gage, Joseph Gardner, Minna Kupfer Golay, Lucy M. Graves, Leonora B. Halstead, John Hitz, Samuel M. Jarvis, George Kennan, Mary S. Logan, Louise, Grand Duchess of Baden, William McKinley, Antoinette Margot, Gustave Moynier, Ellen S. Mussey, Richard Olney, Walter P. Phillips, Joseph Sheldon, Adolphus S. Solomons, F. R. Southmayd, Sara A. Spencer, Edwin M. Stanton, and Henry Wilson.

An Addition series relates primarily to the last years of Barton's life and to the National First Aid Association of America which she established in 1905 to promote first aid training. Mary Isabelle Kensel (later Mary Kensel Wells), Barton's secretary, and Roscoe Green Wells, assistant to the president and commander of the ambulance corps of the association, are featured prominently in this material. Harriette L. Reed, a friend who became president of the association following Barton's death is also represented. Documents include correspondence from Barton to Mary Isabelle Kensel and Roscoe Green Wells regarding their work, annual reports of the National First Aid Association of America, items distributed by the association, including an illustrated triangular bandage, and accounts by Mary Kensel Wells of Clara Barton and the National First Aid Association.