The papers of Gideon Welles (1802-1878), newspaper editor and U.S. secretary of the navy under Presidents Abraham Lincoln and Andrew Johnson, consist of 15,070 items (26,302 images), most of which were digitized from 36 reels of previously produced microfilm. Spanning the years 1777-1911, with the bulk dating from 1820 to 1878, the collection includes correspondence, diaries, writings, naval records, scrapbooks, and other papers relating to Welles's work as editor of the Hartford Times; his activities as a member of the Democratic Party, later the Republican Party, in Connecticut state and national politics; his service as U.S. secretary of the navy; and his literary pursuits. Subjects include slavery, Civil War and Reconstruction, role of the U.S. Navy in the war, Lincoln and Johnson presidential administrations, and the limits and uses of federal and state powers.

Documentation for Welles's political, literary, and personal endeavors is distributed throughout the collection. Welles's administration of the navy is most substantially documented in his diaries and in the series of official letterbooks. The diaries also contain documentation about other cabinet members as well as occasional drafts of prose and poetry, drafts of letters, and travel descriptions.

The Letterbooks record the day-to-day operational and administrative policies enacted by the Navy Department during the Civil War including those related to the establishment of blockades, ship construction and naval ordnance, the outfitting of ironclads, naval engagements and tactical maneuvers, and the pursuit and capture of Confederate cruisers and subsequent rewarding of prize money.

Navy Department records collected by Welles's son, Edgar Thaddeus Welles, while he was employed as chief clerk of the Navy Department, 1865-1869, are mostly concerned with routine administrative detail, especially solicitations for positions and appointments of clerks, midshipmen, surgeon's mates, and other minor officials.

The Correspondence series is composed primarily of political correspondence documenting Welles's commitment to the principles of Thomas Jefferson and Andrew Jackson on both statewide and national levels. The Correspondence series chronicles Welles's withdrawal from the Democratic Party in 1854 over the issue of slavery and the development of the Republican Party. Other correspondence dates from his term of office as secretary of the navy throughout the Civil War and the early years of Reconstruction. Observations of a more personal or family nature are interwoven throughout the correspondence. Welles's letters to his cousin, R. C. Hale, 1833-1835, were written while he was courting Hale's sister, Mary Jane Hale, whom Welles married in June 1835.

As an editorial writer and journalist, Welles contributed many articles on local and national politics to the Hartford Times and, after his retirement in 1869, to The Galaxy External. The Speeches and Writings series contains copies of many of these articles, and material in the Correspondence series reveals interaction between newspaper policy and politics in nineteenth-century America.

The Miscellany series includes correspondence files for Welles's longtime political ally and personal friend, John M. Niles, as well as for Welles's wife Mary Jane and son, Edgar Thaddeus Welles. The Henry B. Learned series contains research material relating to Welles compiled in the course of Learned's research on the executive branch of government.

A card index to correspondents in part of the collection is currently only available in the Manuscript Division Reading Room in Washington, D.C. It is arranged alphabetically by correspondent and identifies items in the Correspondence series, the Records of the Navy Department, and the correspondence files of John M. Niles, Edgar Thaddeus Welles, and Mary Jane Hale Welles. It also lists correspondents other than Gideon Welles in the Miscellany series for the inclusive dates January 1, 1777-February 25, 1828, and March 14, 1860-January 19, 1911.

Correspondents represented in the Gideon Welles Papers include Joseph Pratt Allyn, James F. Babcock, Montgomery Blair, Alfred Edmund Burr, Salmon P. Chase, Edward Spicer Cleveland, Schuyler Colfax, Samuel Sullivan Cox, John Adolphus Bernard Dahlgren, Charles A. Dana, Calvin Day, John A. Dix, James Dixon, James Buchanan Eads, Henry H. Elliott, William Faxon, Orris S. Ferry, David Dudley Field, Andrew H. Foote, John Murray Forbes, Gustavus Vasa Fox, R.C. Hale, Joseph R. Hawley, Mark Howard, Amasa Jackson, Thornton A. Jenkins, Richard M. Johnson, James E. Jouett, Andrew T. Judson, Henry Mitchell, Edwin D. Morgan, John M. Niles, Nathaniel Niles, Jr., Foxhall A. Parker, William Patton, Hiram Paulding, J. J. R. Pease, William V. Pettit, James J. Pratt, Albert Smith, Joseph Smith, Sylvester S. Southworth, Daniel D. Tompkins, Charles Dudley Warner, Thurlow Weed, Edgar Thaddeus Welles, Mary Jane Hale Welles, and Charles Wilkes.

For a more detailed overview of the collection consult the Scope and Content Note in the collection finding aid to the Gideon Welles Papers, which is available online (PDF and HTML) with links to the digital content on this site.

The collection is arranged in ten series:

• Diaries, 1824-1869 (Reels 1-5)
  Contains manuscript diaries and transcripts, diary notes, and journal entries by Welles, including a three-volume retrospective narrative, 1861-1867, and fifteen-volume diary, 1862-1869, written when he was secretary of the navy. Welles's 1862-1869 diaries were excerpted and edited by his son, Edgar Thaddeus Welles, for publication in a three-volume set External in 1911, drafts of which are also included in the series. Items are arranged chronologically.
• Letterbooks, 1862-1869 (Reels 5-8)
  Comprised of letterbooks from the office of the secretary of the navy containing copies of mostly outgoing letters and memoranda of Gideon Welles and other naval officials. Alphabetical name indexes with accompanying subject abstracts are located at the beginning of each volume. The letterbooks are arranged chronologically.
• Correspondence, 1820-1878 (Reels 8-27)
  Includes letters sent and received by Gideon Welles. The correspondence is arranged chronologically.
• Records of the Navy Department, 1805-1878 (Reels 26-29)
  Contains letters of application and recommendation for appointed commissions, memoranda, documents, and reports from the office of the secretary of the navy. The material is arranged chronologically.
• Speeches and Writings, 1822-1878 (Reels 29-31)
  Consists of manuscript drafts, fair copies, transcripts, printed copies, and notebooks for Welles's articles and speeches. The material in the series is arranged alphabetically by type of document and thereunder alphabetically by title.
• Scrapbooks, 1834-1900 (Reels 31-33; Reel 36)
  Includes newspaper clippings and copies of published articles by Welles that are arranged chronologically.
• Miscellany, 1777-1911 (Reels 33-35)
  Comprised of correspondence, financial and legal documents, printed matter, cards and invitations, collected speeches and writings by others, and notes. The series is arranged alphabetically by type of material. Researchers interested in the correspondence of Edgar T. Welles will also want to consult the Mary Jane Welles correspondence in the Miscellany series, as some correspondence addressed to Edgar T. Welles is contained therein.
• Henry B. Learned Papers, 1899-1911 (Reels 35-36)
  Consists of research material compiled by historian Henry B. Learned relating to Welles, including transcripts of articles and correspondence written by Welles, research notes, other correspondence, printed matter, and writings. The series is arranged alphabetically by type of material.
• Oversize, 1842-1860 (Reel 36)
  The Oversize series consists of vol. 2 of Welles's scrapbooks, 1842-1860. This item is stored in an oversize container in the physical collection and was microfilmed at the end of Reel 36.
• Additions, 1822-1877 (Not filmed; scanned from originals)
  Includes correspondence and drafts of writings. The two additions in this series, covering respectively the years 1822-1877 and 1873-1877, are organized by their respective dates of processing, and therein by type of material or topic.