Letters and papers to or from American scientists or about America, selected from the Linnean Society's collections. Includes letters to William Swainson from John Abbott, John J. Audubon, Constantine S. Rafinesque, Isaac Lea, and John E. LeConte; letters to Sir James Edward Smith from Jacob Bigelow, DeWitt Clinton, J.F. Correia da Serra, David Hosack, Theodore Lyman, William Dandridge Peck, Rafinesque, and Gotthilf H.E. Muhlenberg; letters to William Darlington; letters to Asa Gray; letters of John Bartram; letters of Peter Collinson to J.F. Gronovius; letters and papers of John Ellis, including letters from Alexander Garden, Samuel Martin, and Bernard Romans; letters to Carl Linnaeus from John Bartram, John Clayton, Cadwallader Colden, Correia da Serra, Peter Kalm, Adam Kuhn, James Logan, John Mitchell, and Charles Wrangel.

Principal correspondents in the lettes of John Fries Frazer include Alexander Dallas Bache, Louis Agassiz, Joseph Henry, and Titian Ramsay Peale who discuss mainly general scientific topics, although personal and family matters are discussed with Bache. Topics include the University of Pennsylvania, boiler explosions, chemistry, education, the National Academy of Sciences, the Smithsonian Institution, fossils, magnetism, solar eclipses, the American Philosophical Society, weights and measures, the U.S. Coast and Geodetic Survey, scientific instruments, the American Civil War, electricity, the United States Mint, the Franklin Institute, scientists of the period, natural history, and publications.