north to the nitrate-rich Tarapacá area, which Chile had seized from Peru 10 years earlier. Tarapacá was, by that time, Chile's richest region in terms of natural resources and was without the fleet practically out of reach for the Chilean Army. From here, the navy organized an army made of nitrate miners, whom they armed and trained to face the 40,000-men-strong Army of Chile. In August 1891, the new army was disembarked in Quintero and defeated the Chilean Army at the Battle of Concón and the Battle of Placilla before the presidential faction disbanded and the congressional side took power. On the elections of October 1891, Jorge Montt was elected president. Not all navy officers sided with the congress. Some like Juan Williams Rebolledo, Juan José Latorre and Policarpo Toro remained on the presidential side and Francisco Vidal Gormaz declared his neutrality. After the war these officers were removed from their offices. In contrast to these officers whose career or influence in the navy was truncated by the war, the 1891 Chilean Civil War served as a starting point of a successful career in the navy for a generation of young officers like Francisco Nef and others who sided with the congressionals who won the war. After incidents with Chile in 1872, 1877, and 1878, Argentina had decided that a brown-water navy, even if modern, was not enough to back up its ambitions in Patagonia and the South Atlantic. Both countries were distracted in the next few years by Argentina's internal military operations against natives and Chile's War of the Pacific against Bolivia and Peru, but by 1890, a full-fledged naval arms race was underway between the two. The Boundary treaty of 1881 between Chile and Argentina had been a major success in laying the groundwork for nearly all of Chile and Argentina's of shared borders, but the drawing of boundaries in the largely unexplored inland Patagonia soon became a major source of territorial disputes. Over the 1880s and 1890s, Chile and Argentina engaged in an arms race fueled by nationalistic rhetoric and tax income from their blooming economies. Both countries signed a treaty in 1902 to end the arms race. During the 1890s, the Chilean Navy carried out many hydrographic surveys in the Patagonian channels aimed to improve navigation, and explored the river basins of Patagonia. A German geographer, Hans Steffen, led navy explorations to western Patagonia, laying the