[1] Prior to the signing of the Treaty of Ampala, in the late 1880s, Guatemalan President Manuel Barillas pushed the idea in Guatemala and neighboring El Salvador and Honduras to recreate a Central American union like the long-dissolved Federal Republic of Central America.

[2] On 22 June 1890, however, Salvadoran President Francisco Menéndez was assassinated and his successor, Carlos Ezeta, pulled out of the treaty, effectively killing the union before it was even formed.

[2] Guatemala refused to recognize Ezeta's presidency and declared war on El Salvador on 27 June 1890.

The United States sent warships to the coasts of El Salvador and Guatemala to protect American interests in both countries and put pressure on both governments to end the war which the two agreed to do so on 21 August 1890.

[4] This article incorporates public domain material from "A Guide to the United States' History of Recognition, Diplomatic, and Consular Relations, by Country, since 1776: El Salvador".