Argentina, officially the Argentine Republic (), is a federal republic in the southern portion of South America. Sharing the bulk of the Southern Cone with its neighbor Chile to the west, the country is also bordered by Bolivia and Paraguay to the north, Brazil to the northeast, Uruguay and the South Atlantic Ocean to the east, and the Drake Passage to the south. With a mainland area of , Argentina is the eighth-largest country in the world, the second largest in Latin America, and the largest Spanish-speaking one. The country is subdivided into twenty-three provinces (, singular "provincia") and one autonomous city ("ciudad autónoma"), Buenos Aires, which is the federal capital of the nation () as decided by Congress. The provinces and the capital have their own constitutions, but exist under a federal system. 

Argentina claims sovereignty over part of Antarctica, the Falkland Islands (), and South Georgia and the South Sandwich Islands. The earliest recorded human presence in the area of modern-day Argentina dates back to the Paleolithic period. The country has its roots in Spanish colonization of the region during the 16th century. Argentina rose as the successor state of the Viceroyalty of the Río de la Plata, a Spanish overseas viceroyalty founded in 1776. The declaration and fight for independence (1810–1818) was followed by an extended civil war that lasted until 1861, culminating in the country's reorganization as a federation of provinces with Buenos Aires as its capital city. The country thereafter enjoyed relative peace and stability, with massive waves of European immigration radically reshaping its cultural and demographic outlook. The almost-unparalleled increase in prosperity led to Argentina becoming the seventh wealthiest developed nation in the world by the early 20th century.
How did it become the capitol?
Buenos Aires, which is the federal capital of the nation () as decided by Congress