May Revolution
The May Revolution was a direct reaction to Spain's Peninsular War. In 1808, King Ferdinand VII of Spain abdicated in favor of Napoleon, who granted the throne to his brother, Joseph Bonaparte. A Supreme Central Junta led resistance to Joseph's government and the French occupation of Spain, but eventually suffered a series of reversals that resulted in the Spanish loss of the northern half of the country. On February 1, 1810, French troops took Seville and gained control of most of Andalusia. The Supreme Junta retreated to Cadiz and dissolved itself, and the Council of Regency of Spain and the Indies replaced it. News of these events arrived in Buenos Aires on May 18, brought by British ships.
May Day riots of 1894
One of the major causes of the riots was the Panic of 1893. The panic precipitated one of the most severe depressions in American History. The closure of two major railroads and other major companies triggered a stock market collapse. The New York banks had heavily invested in the stock market, and bank failures soon began. This caused a contraction of credit, and many other, newer, businesses started to shut down as well. The depression produced widespread social unrest, mostly among the now-unemployed workers. Some people tried to create public works programs for the unemployed, but this was unsuccessful.