Filibuster War

Filibuster War
	; The National Monument of Costa Rica in San José depicting the countries of Central America triumphing over filibuster William Walker
Date	16 June 1855 – 1 May 1857; (1 year, 10 months, 2 weeks and 1 day)
Location	Nicaragua with spillovers in Costa Rica
Result	Central American alliance victory
Belligerents
Filibusters; Walker's Nicaragua; Democratic Party;	Allied Central American Army Nicaragua; Costa Rica; El Salvador; Guatemala; Honduras; ; Legitimist Party;
Commanders and leaders
William Walker ; Charles Henningsen; Byron Cole †; Birkett D. Fry; Patricio Rivas; Francisco Castellón #; Nazario Escoto; Ponciano Corral ; Trinidad Muñoz †;	Tomás Martínez; Máximo Jerez; José María Estrada X; Ponciano Corral ; Juan Rafael Mora; José Joaquín Mora; José María Cañas; Ramón Belloso; Gerardo Barrios; Mariano Paredes; Florencio Xatruch; Sylvanus Spencer;
Strength
Per Henningsen:; 2,518 total;	Per Henningsen:; 17,800 total 6,300 (Nicaraguans); 11,500 (allies); ;
Casualties and losses
Per Henningsen:; 1,000 killed in action or died to disease; 80 captured; 700 deserted;	Per Henningsen:; 5,860 killed or wounded; Unknown died to disease;
	9,615 died to cholera in Costa Rica

The Filibuster War, also referred to the Walker affair and known in Costa Rica as the National Campaign of 1856–1857, was a war fought in Central America between 1855 and 1857. The militaries of Costa Rica, El Salvador, Guatemala, Honduras, and Nicaragua established the Allied Central American Army and fought against American filibusters led by William Walker who had taken over the Nicaraguan government.

In 1854, the Democratic Party of Nicaragua led by Francisco Castellón launched a rebellion against the Legitimist government of President Fruto Chamorro. During the war, American businessman Byron Cole became acquainted with Castellón and convinced him to invite American filibusters led by Walker to militarily support his faction. Walker's force of 58 men arrived in Nicaragua in June 1855. Walker captured the Legitimist capital of Granada in October 1855 and established a government with Patricio Rivas as its president, however, Walker held the real power.

In March 1856, Costa Rica declared war on Walker's government. Filibusters invaded Costa Rica but were defeated at the Battle of Santa Rosa. Costa Rican president Juan Rafael Mora led a counterattack the following month and defeated the filibusters at the Second Battle of Rivas, but Mora withdrew due to a cholera outbreak among his troops. The governments of El Salvador and Guatemala soon sent soldiers to help overthrow Walker and the filibusters suffered defeats at San Jacinto and Masaya. Walker lost control of Granada, the capital in December 1856. Walker surrendered to United States Navy commander Charles Henry Davis on 1 May 1857.

Walker attempted two further expeditions to Nicaragua in late 1857 and mid 1860 but both ended in his arrest, the former by the U.S. Navy and the latter by the Royal Navy. Walker was handed over to Honduran authorities and executed in September 1860. Walker's takeover of Nicaragua and U.S. diplomatic support of his government through U.S. minister John H. Wheeler strained Central America–United States relations.