The complete Abraham Lincoln Papers at the Library of Congress consists of approximately 20,000 items, including correspondence and enclosures, drafts of speeches, and notes and printed material. Most of the items are from the 1850s through Lincoln's presidential years. However, there are some documents from Lincoln's term as a member of the House of Representatives (1847-49) related to the Mexican War and its aftermath.

The papers of U.S. Army officer and governor of New Jersey George Brinton McClellan (1826-1885) consist of 33,000 items (59,477 images), most of which were digitized from 82 reels of previously produced microfilm. Spanning the years 1783-1898, with the bulk dating from 1850 to 1885, the collection contains correspondence, telegrams, memoranda, diaries, writings, notes, military papers, McClellan family papers, scrapbooks, printed copies of speeches, articles and books, and other papers. The collection includes letters from when he served during the Mexican War.

The papers of James K. Polk (1795-1849), governor of Tennessee, representative from Tennessee, Speaker of the House of Representatives, and eleventh president of the United States, contain approximately 20,500 items dating from 1775 to 1891, with the bulk falling in the period 1830-1849.

The papers of Ulysses S. Grant (1822-1885), army officer and eighteenth president of the United States, contain approximately 50,000 items dating from 1819-1974, with the bulk falling in the period 1843-1885. They include general and family correspondence, speeches, writings, reports, messages, military records, financial and legal records, newspaper clippings, scrapbooks, memorabilia, and other papers. The collection relates to Grant's service in the Mexican War and Civil War, his pre-Civil War career, and his postwar service as U.S. secretary of war ad interim under President Andrew Johnson, his 1868 presidential campaign and two-term presidency, his unsuccessful 1880 presidential bid, and his extensive travels and financial difficulties.

The Zachary Taylor Papers contains approximately 650 items dating from 1814 to 1931, with the bulk from 1840 to 1861. The collection is made up primarily of general correspondence and family papers of Taylor (1784-1850), with some autobiographical material, business and military records, printed documents, engraved printed portraits, and other miscellany relating chiefly to his presidency (1849-1850); his service as a U.S. Army officer, especially in the 2nd Seminole Indian War; management of his plantations; and settlement of his estate. Also included are materials about property division among the Taylor family and operation of son Richard Taylor’s sugar plantation after President Taylor’s death.

This category contains maps showing campaigns of major military conflicts including troop movements, defensive structures and groundworks, roads to and from sites of military engagements, campsites, and local buildings, topography and vegetation. The collection includes maps from the Mexican War.

Historic American newspapers selected and contributed by state partners in the National Digital Newspaper Program. Search this collection to find newspaper articles about the Mexican War.

This collection consists of over 15,000 pieces of sheet music registered for copyright during the years 1820 to 1860. Included are popular songs, operatic arias, piano music, sacred and secular vocal music, solo instrumental music, method books and instructional materials, and some music for band and orchestra. There are more than fifty pieces of sheet music written about the Mexican War in this collection.