At the time of independence, Uruguay had an estimated population of just under 75,000, of which less than 20 percent resided in Montevideo, the capital. Indeed, the new nation was born with most of its population scattered throughout the countryside. Political power centered on local leaders, or caudillos, who attracted followers because of their power, bravery, or wealth. There were three major caudillos at the time of independence: Rivera, Oribe, and Lavalleja. The first two were later elected presidents, Rivera from 1830 to 1835 and from 1838 to 1843 and Oribe from 1835 to 1838. Their rivalry, which turned violent in 1836, led to the formation of the first political groups, known as Colorados and Blancos because of the red and white hatbands, respectively, worn during armed clashes beginning in 1836. The groups would subsequently become the Colorado Party and the National Party (the Blancos).
During this period, the economy came to depend increasingly on cattle, on the proliferation ofsaladeros (meat-salting establishments), and on the export of salted beef and leather. But political instability was the most significant feature of this period. Caudillos and their followers were mobilized because of disputes arising from deficient land demarcation between absentee landowners and squatters and between rightful owners and Artigas's followers who were granted land seized by Artigas. Rivera remained in the countryside for most of his presidency, during which Lavalleja organized three unsuccessful rebellions. Rivera was followed as president by Oribe, one of the ThirtyThree Heroes, but they began to quarrel after Oribe permitted Lavalleja and his followers to return from Brazil. In 1836 Rivera initiated a revolutionary movement against President Oribe, but Oribe, aided by Argentine troops, defeated Rivera's forces at the Battle of Carpintería on September 19, 1836. In June 1838, however, the Colorados, led by Rivera, defeated Oribe's Blanco forces; Oribe then went into exile in Buenos Aires.
Internationally, the new territory was at the mercy of the influence of its neighbors. This resulted from its lack of clearly defined borders, as well as from Rivera's ties with Brazil and Oribe's with Argentina.