Letters and papers relating to Sparks's research on Benjamin Franklin and the publication of an edition of the latter's writings. There are also extracts from Sparks's journal, 1831-1841, relating to his Franklin researches.

These selected papers include correspondence concerning Franklin, Franklin's descendants, and Franklin's papers, extracts from Philadelphia newspapers on Franklin, papers used in Sparks' biography, miscellaneous entries in his diary (1830-1854) relating to his search for Franklin manuscripts, and his preparation of an edition of Franklin's writings. Correspondents include Henry Stevens, Jr.; Henry Stevens, Sr.; Benjamin Vaughan; Petty Vaughan; James Mease; H. D. Gilpin; J. Francis Fisher; Franklin Bache; and others.

Alexander Dallas Bache (1806-1867) was an important scientific reformer during the early nineteenth century. From his position as superintendent of the United States Coast Survey, and through leadership roles in the scientific institutions of the time, Bache helped bring American science into alignment with the professional nature of its European counterparts. In addition, Bache fostered the reform of public education in America. The Alexander Dallas Bache Collection consists of 91 letters written primarily by Bache. In most cases, these are brief notes replying to letters that are not part of the collection. The majority of items relate to Bache's work as superintendent of the U.S. Coast Survey, including letters of recommendation and introduction, and there is minor correspondence regarding the National Academy of Sciences, scientific matters, his travels in Europe, or personal matters. Of particular interest is the letter from Louis Agassiz in 1856 expressing his view of what the natural history museum of the future should be.

Though the Miscellaneous Manuscripts collection is composed of items that do not fall readily into any other existing collection, the two dominant intellectual areas represented in the collection are Early American History and History of Science.