Of the five Central American countries, only Honduras supported Barrios' reunification effort; Costa Rica, El Salvador, and Nicaragua opposed it, as did Mexico.

[5] The federal republic eventually dissolved in 1839 following two civil wars and the overthrow of President Francisco Morazán, resulting in the independence of Costa Rica, El Salvador, Guatemala, Honduras, and Nicaragua.

[9] A convention between El Salvador and Honduras in 1842 elected Antonio José Cañas as president of a new federation, but the remaining republic refused to recognize his authority.

[citation needed] El Salvador called for assistance from Mexico to distract the Guatemalans while they prepared their army.

The Guatemalans attempted to negotiate with the Mexicans through the United States' ambassador to Guatemala, Antonio Batres Jáuregui.

[citation needed] After Barrios' death, Alejandro M. Sinibaldi became acting president of Guatemala, who was then succeeded by Barillas shortly afterwards.

[18] Costa Rican President Próspero Fernández Oreamuno died in office during the war and was succeeded by Bernardo Soto Alfaro.

[20] On 15 November 1886, Barillas sent a message to the leaders of Costa Rica, Honduras, and Nicaragua to send delegates to Guatemala City in order to discuss maintaining peace in Central America.

On 16 February 1887, the delegates drafted a treaty of peace and amity and continued negotiations in 1888 and 1889 to form a federation through diplomatic means.