John Appleton (February 11, 1815 – August 22, 1864) was an American lawyer, politician and diplomat who served as the United States' first chargé d'affaires to Bolivia, and later as special envoy to Great Britain and Russia.

[9] His closeness to Polk continued while in this role, culminating in an invitation to act as the President's personal diarist for a goodwill tour of the northeastern states.

"[11] Describing the region's largest city, Appleton wrote: New York ... has the social faults which belong to an eminently business place, and to a shifting, moneymaking people.

[14] His primary instructions were to open economic relations with Bolivia, assure them of United States' goodwill and help secure a cross-border treaty that would transfer the port of Arica from Peruvian to Bolivian control.

[15] Buchanan further urged Appleton to use his influence as chargé d'affaires to encourage Bolivia towards democracy, by "presenting to them the example of our own country, where all controversies are decided at the ballot box.

However his arrival was delayed first by the shipwreck of the USS Onkahye, which had been carrying him to South America, and then by slow progress through the Andes Mountains en route to La Paz.

[9][17] In October he reached the Bolivian capital to discover that the government of President José Miguel de Velasco Franco was besieged by soldiers under the command of former Minister for War Manuel Isidoro Belzu.

[19] Attempts to deliver on Buchanan's instructions for a cross-border treaty with Peru were also rebuffed, as the Peruvian Government had not been advised that Appleton would be undertaking this task and declined to negotiate with him.

[21] When God shall send his angel to us, Mr. Speaker, bearing the scroll of death, may we be able to bow our heads to his mission with as much gentleness and resignation as marked by the last hours of Daniel Webster.

[23] His focus was now on European affairs, taking a conservative line against international republicanism and political reform which he felt was motivated by emotion rather than reason.

For Appleton, European republican sentiment was "like the fabled Phaeton, [who] seizes the reins with passion, drives madly off the course, and nearly engulfs the world in darkness.

His speaking skills were recognized in December 1852 when he was chosen by Congress to read the obituary address for former Senator and Secretary of State Daniel Webster.

[7] Instead he returned to Maine, and in February 1855 was appointed as diplomatic envoy to London, England, with instructions to lead United States engagement in negotiations to end the Crimean War.

[7] Appleton was subsequently nominated as United States chargé d'affaires in London, but declined the position and returned home to assist James Buchanan's Presidential campaign.

Talks were held in Washington between Appleton, Russian representative Eduard de Stoeckl and chairman of the U.S. Senate Committee on Naval Affairs William M. Gwin.