LA PLATA, Rio de, reo da, an estuary on the southeastern coast of South America, between Uruguay and Argentina; an outlet for the united waters of the Parana and Uruguay rivers. The enormous outflow, estimated at 2,000,000 cubic feet per second, which in volume is exceeded only by that of the Amazon, creates powerful currents; treacherous shallows are formed over the washings brought down from the interior of the continent; and the low-lying southern shores afford no shelter from storm winds. Therefore navigation in this estuary, which is 143 miles wide at its mouth, and about 190 miles long, narrowing gradually above Montevideo and Buenos Aires, combines the perils of river and open sea. On the north shore there is one good natural harbor — that of Montevideo; on the Argentine side well directed efforts are being made to supply natural deficiencies by building massive docks, dredg ing deep-water channels and completung other extensive harbor improvements BUENOS AIRES; and LA PLATA )1''' the region to which the Rio de la Plata, with the Uruguay, Parana and Paraguay rivers, gives access, is of vast extent. The estuary was discovered in 1509 by Diaz de Solis, received its name (silver river) from Sebastian Cabot, and was explored by Day in 1853 and by Page from 1853 to 1856.
In the later years of Spanish dominion it was comprised in the vice-royalty of La Plata, from which the states of Argentina, Uruguay, Para guay and Bolivia have been carved; and to-day the southern portions of that region sustain some of the most progressive of all Latin American communities. Early in the last cen tury Great Britain attempted to secure control of this continental gateway, a position which, as it now appears, would have enabled her to win in the south a colony possessing very great resources — another Canada, at least. In 1806, when England and Spain were at war, Spain being the ally of Napoleon, Maj.-Gen. William Carr Beresford, with about 1,600 men, arrived off Buenos Aires, and captured the city quite easily. But a few weeks later the invaders were driven out. A much larger army, com manded by General Whitelocke, was sent in 1808 to recapture Buenos Aires, and a separate force succeeded in taking possession of Monte video. But the British were defeated on the south shore; General Whitelocke capitulated on the day of the withdrew to his ships and surrendered Montevideo.