Principal Officers and Chiefs of Mission, by year: 1864
Note: Career Foreign Service appointees are asterisked.
- Adams, Charles Francis (1807-1886)
- Envoy Extraordinary and Minister Plenipotentiary, United Kingdom (1861-1868)
- Burlingame, Anson (1820-1870)
- Envoy Extraordinary and Minister Plenipotentiary, Austria (1861)
- Envoy Extraordinary and Minister Plenipotentiary, China (1861-1867)
- Burton, Allan A. (?-?)
- Minister Resident, Colombia (1861)
- Minister Resident, Colombia (1861-1864)
- Campbell, James Hepburn (1820-1895)
- Minister Resident, Sweden (1864-1867)
- Minister Resident, Colombia (1866)
- Clay, Cassius Marcellus (1810-1903)
- Envoy Extraordinary and Minister Plenipotentiary, Spain (1861)
- Envoy Extraordinary and Minister Plenipotentiary, Russia (1861-1862)
- Envoy Extraordinary and Minister Plenipotentiary, Russia (1863-1869)
- Clay, Thomas Hart (1803-1871)
- Minister Resident, Nicaragua (1862-1863)
- Minister Resident, Honduras (1863-1866)
- Corwin, Thomas (1794-1865)
- Envoy Extraordinary and Minister Plenipotentiary, Mexico (1861-1864)
- Crosby, Elisha Oscar (1818-1895)
- Minister Resident, Guatemala (1861-1864)
- Dayton, William Lewis (1807-1864)
- Envoy Extraordinary and Minister Plenipotentiary, France (1861-1864)
- Dickinson, Andrew B. (?-?)
- Minister Resident, Nicaragua (1861-1863)
- Minister Resident and Extraordinary, Nicaragua (1863-1869)
- Fogg, George Gilman (1813-1881)
- Minister Resident, Switzerland (1861-1865)
- Haldeman, Jacob Samils (1827-1889)
- Minister Resident, Sweden (1861-1864)
- Hale, Charles (1831-1882)
- Agent/Consul General, Egypt (1864-1870)
- Assistant Secretary of State (1872-1873)
- Hall, Allen A. (?-1867)
- Minister Resident, Bolivia (1863-1867)
- Hanson, Abraham (?-1866)
- Commissioner and Consul General, Liberia (1863-1866)
- Harvey, James E. (1820-?)
- Minister Resident, Portugal (1861-1869)
- Hassaurek, Frederick (Friedrich) (1831-1885)
- Minister Resident, Ecuador (1861-1866)
- Judd, Norman Buel (1815-1878)
- Envoy Extraordinary and Minister Plenipotentiary, Germany (1861-1865)
- Kellogg, William (1814-1872)
- Minister Resident, Guatemala (1864)
- King, Rufus (1814-1876)
- Minister Resident, Holy See (1861)
- Minister Resident, Holy See (1863-1867)
- Kirk, Robert C. (1821-?)
- Minister Resident, Argentina (1862-1866)
- Minister Resident, Uruguay (1869-1870)
- Minister Resident, Argentina (1869-1871)
- Koerner, Gustavus (1809-1896)
- Envoy Extraordinary and Minister Plenipotentiary, Spain (1862-1864)
- Marsh, George Perkins (1801-1882)
- Minister Resident, Turkey (1849-1853)
- Envoy Extraordinary and Minister Plenipotentiary, Italy (1861-1882)
- McBride, James (1802-1875)
- Minister Resident, Hawaii (1863-1866)
- Morris, Edward Joy (1815-1881)
- Chargé d'Affaires, Two Sicilies (1850-1853)
- Minister Resident, Turkey (1861-1870)
- Motley, John Lothrop (1814-1877)
- Ambassador Extraordinary and Plenipotentiary, Austria (1861-1867)
- Ambassador Extraordinary and Plenipotentiary, United Kingdom (1869-1870)
- Nelson, Thomas Henry (1824-1896)
- Envoy Extraordinary and Minister Plenipotentiary, Chile (1861-1866)
- Envoy Extraordinary and Minister Plenipotentiary, Mexico (1869-1873)
- Pike, James Shepard (1811-1882)
- Minister Resident, Netherlands (1861-1866)
- Pruyn, Robert Hewson (1815-1882)
- Minister Resident, Japan (1861-1865)
- Riotte, Charles N. (?-?)
- Minister Resident, Costa Rica (1861-1867)
- Minister Resident, Nicaragua (1861-1867)
- Minister Resident, Costa Rica (Not commissioned; nomination tabled by the Senate.)
- Sanford, Henry Shelton (1823-1891)
- Minister Resident, Belgium (1861-1869)
- Minister Resident, Belgium (Not commissioned; nomination not confirmed by the Senate.)
- Minister Resident, Spain (Not commissioned; nomination not confirmed by the Senate.)
- Seward, Frederick William (1830-1915)
- Assistant Secretary of State (1861-1869)
- Assistant Secretary of State (1877-1879)
- Seward, William Henry (1801-1872)
- Secretary of State (1861-1869)
- Washburn, Charles Ames (1822-1889)
- Commissioner, Paraguay (1861)
- Minister Resident, Paraguay (1863-1868)
- Webb, James Watson (1802-1884)
- Chargé d'Affaires, Austria (1849-1850)
- Minister Resident, Turkey (1861)
- Envoy Extraordinary and Minister Plenipotentiary, Brazil (1861-1869)
- Whidden, Benjamin F. (?-?)
- Commissioner and Consul General, Haiti (1862-1865)
- Wood, Bradford Ripley (1800-1889)
- Minister Resident, Denmark (1861-1865)