Federales was the name under which the supporters of federalism in Argentina were known, opposing the Unitarios that claimed a centralised government of Buenos Aires Province, with no participation of the other provinces of the custom taxes benefits of the Buenos Aires port. The Federales supported the autonomy of the provincial governments and the distribution of external commerce taxes among the provinces. In general, the Federals were provincial governors and leaders, some of which became caudillos, such as Juan Facundo Quiroga.
 Early conflict
The Argentine War of Independence saw the forces of the United Provinces of the Río de la Plata fighting Spanish royalists who attempted to regain control of their American colonies after the Napoleonic Wars. After the victorious May Revolution of 1810, disagreements arose between the dominant province of Buenos Aires, who were known as Unitarios, and the other provinces of Argentina, known as the Federalists. These were evident at least as early as the declaration of Argentine independence in 1816. The Unitarios lost their controlling power after the Battle of Cepeda (1820), which was followed by several months of anarchy. However, the Unitarios were forced to sign a treaty with other provinces. This did not solve the conflicts between the Federalists and the Unitarians.
Under president Bernardino Rivadavia (1826–1827), the Unitarians gained control for a short period of time. The Constitution of 1826 allowed for a balance between the ideas of Unitarians and Federalists: “It provided for a centralized national authority while leaving the provinces with considerable local powers.” However, the constitution was rejected by provincial caudillos, military leaders, and the conflict continued.
 Unitarian League
In 1829, the Unitarian League (Spanish: Liga Unitaria) was created by General José María Paz in order to defeat the Federalists,easily taking power in nine provinces. The Federalist governments of Buenos Aires, Santa Fe, Entre Ríos and Corrientes, united under the Federal Pact, confronted Paz and his troops on May 31, 1831. The Unitarios were defeated after Paz was captured by the troops of Santa Fe Governor, Estanislao López.
 Gaucho Federalists
Also in 1829, Juan Manuel de Rosas, the boss of a troop of Gaucho Federalists, became governor of Buenos Aires after defeating General Lavalle, who was then forced into exile. Although Rosas was a Federalist, he kept the customs receipts of Buenos Aires under the exclusive control of the city, whereas the other provinces expected to have a part of the revenue. Rosas considered that this was a fair measure because only Buenos Aires was paying the external debt generated by the Baring Brothers loan to Rivadavia, the war of independence and the war against Brazil.
Afterward, many men (perhaps most notably, Juan Lavalle) attempted to defeat Rosas in what became a series of civil wars that lasted nearly two more decades. With support from other provinces, Justo José de Urquiza, caudillo of Entre Ríos Province, finally defeated Rosas at the Battle of Caseros on February 3, 1852. That May, the San Nicolás Agreement was signed by the provincial governors. The pact reinstated the treaty signed in 1831 by Argentina and the interior provinces and called for a constitutional convention.
 Federal Constitution
In 1853, the Unitarios of Buenos Aires broke away from the interior provinces after Urquiza nationalized customs receipts and allowed free flow of trade on the Parana and Uruguay rivers. In 1859, Buenos Aires was forced to accept the federal constitution of 1853 after six years of secession. This was because on October 23, Mitre was defeated at Cepeda by Urquiza. However, the federal constitution was “amended to allow Buenos Aires greater influence.” After the Battle of Pavón, Mitre was chosen president of a new national government.
Opposition to the Unitarios continued until 1890 under the Córdoba League.
The several armed conflicts between Federales and Unitarios that started after the May Revolution of 1810, diminished with the Federalist Justo José de Urquiza's betrayal and defeat over the governor of Buenos Aires, Juan Manuel de Rosas at the Battle of Caseros in 1852, and ended in 1862 when Bartolomé Mitre was named president.
- "Unitario" Encyclopædia Britannica. 2008. Encyclopædia Britannica Online. 3 Nov. 2008 <http://search.eb.com/eb/article-9100157>.
- "Cepeda, battles of" Encyclopædia Britannica. 2008. Encyclopædia Britannica Online. 5 Nov. 2008 <http://search.eb.com/eb/article-9022115>.
- Crow, John A. (1992) he Epic of Latin America. University of California Press. ISBN 978-0-520-07723-2.
 See also