In what year did Uruguay become fully independent? The answer is 1828.
Uruguay’s independence was recognized through the Preliminary Peace Convention of 1828, which ended the Cisplatine War between Brazil and the United Provinces of the Río de la Plata. The agreement established the former Cisplatine Province as a separate, free, and independent state.
The settlement followed a long struggle over the territory. Uruguay’s independence movement had declared separation from Brazil and sought union with the United Provinces in 1825, but fighting continued. British mediation helped Brazil and the United Provinces accept an independent Uruguay as a buffer state between them.
The key date is sometimes confused with 1825, the year of the independence declaration, or 1830, when Uruguay’s first constitution was sworn. The treaty was signed on August 27, 1828, and its ratifications were exchanged in Montevideo on October 4. Thus, 1828 marks international recognition and effective independence, while 1830 marks constitutional organization.