In 1899 the Liberal Party overthrew the Conservatives in the "Federal Revolution." Although the Liberals resented the long rule of the Conservatives, the main reasons for the revolt were regionalism and federalism. The Liberal Party drew most of its support from the tin-mining entrepreneurs in and around La Paz, whereas Conservative governments had ruled with an eye on the interests of the silver mine owners and great landowners in Potosí and Sucre. The immediate cause of the conflict was the Liberal demand to move the capital from Sucre to the more developed La Paz.

The Federal Revolution differed from previous revolts in Bolivia in that Indian peasants actively participated in the fighting. Indian discontent had increased because of the massive assault on their communal landholdings. The campesinos supported the Liberal leader, José Manuel Pando, when he promised to improve their situation.

Pando, however, reneged on his promises and allowed the assault on Indian land to continue. The government suppressed a series of campesino uprisings and executed the leaders. One of these revolts, led by Pablo Zárate Willka, was one of the largest Indian rebellions in the history of the republic. It frightened whites and mestizos, who once again successfully isolated the Indians from national life.

Like their Conservative predecessors, the Liberals controlled the presidential elections but left the elections for the Congress relatively free. They also continued to professionalize the Bolivian military, with the aid of a German military mission (see Evolution of the Military Role in Society and Government , ch. 5). President Ismael Montes Gamboa (1904-09 and 1913-17) dominated the Liberal era.

Liberal administrations gave priority to the settlement of border disputes. Bolivia's inability to protect and integrate the frontier with Brazil had led to the encroachment of Brazilian rubber gatherers. In 1900 they began an active secessionist movement in the eastern province of Acre and after three years of small-scale fighting won annexation by Brazil. In the Treaty of Petropolis in 1903, Bolivia relinquished its claims to 191,000 square kilometers of Acre territory in return for two areas on the Madeira and the Paraguay rivers totaling 5,200 square kilometers, the equivalent of US$10 million, and the use of a railroad to be constructed around the rapids of the Madeira in Brazilian territory. In 1904 Bolivia finally concluded a peace treaty with Chile under which it officially ceded Bolivia's former territory on the coast in return for indemnification of US$8.5 million, less the value of the Bolivian section of a new railroad that Chile would construct from La Paz to the Pacific Coast at Arica. The payment was used to expand the transportation system in Bolivia. By 1920 most major Bolivian cities were connected by rail.

Liberal governments also changed the seat of government and the nature of church-state relations. The presidency and the Congress were moved to La Paz, which became the de facto capital, but the Supreme Court of Justice remained in Sucre. Liberal presidents canceled the special privileges officially granted to the Roman Catholic Church. In 1905 they legalized public worship by other faiths, and in 1911 they made civil marriage a requirement.

Perhaps the most significant development of the Liberal era was the dramatic rise of Bolivian tin production. Since the colonial period, tin had been mined in the Potosí region; nonetheless, Bolivia historically lacked the transportation system necessary to ship large quantities of tin to European markets. The extension of the rail link to Oruro in the 1890s, however, made tin mining a highly profitable business. The decline in European tin production also contributed to the Bolivian tin boom at the beginning of the twentieth century. With the development of huge mines in southern Oruro and northern Potosí, La Paz eclipsed Potosí as the mining industry's financial and service center.

Tin production in Bolivia came to be concentrated in the hands of Bolivian nationals, although the regimes encouraged foreign investment. At first, foreign interests and Bolivians with foreign associations took the major share. This changed, however, when Bolivian tin-mining entrepreneurs realized that smelters in competing countries depended on Bolivian tin. Simón Patiño was the most successful of these tin magnates. Of poor mestizo background, he started as a mining apprentice. By 1924 he owned 50 percent of the national production and controlled the European refining of Bolivian tin. Although Patiño lived permanently abroad by the early 1920s, the two other leading tin-mining entrepreneurs, Carlos Aramayo and Mauricio Hochschild, resided primarily in Bolivia.

Because taxes and fees from tin production were critically important to national revenues, Patiño, Aramayo, and Hochschild exercised considerable influence over government policy. Unlike the silver-mining entrepreneurs of the Conservative period, the tin-mining magnates did not directly intervene in politics but employed politicians and lawyers--known as the rosca (see Glossary) --to represent their interests.

The tin boom also contributed to increased social tensions. Indian peasants, who provided most of the labor for the mines, moved from their rural communities to the rapidly growing mining towns, where they lived and worked in precarious situations. Bolivia's First National Congress of Workers met in La Paz in 1912, and in the following years the mining centers witnessed an increasing number of strikes.

Liberal governments at first did not face any serious opposition because the Conservative Party remained weak after its overthrow in 1899. By 1914, however, opposition to political abuses and the loss of national territory led to the formation of the Republican Party (Partido Republicano). Republican support increased when mineral exports declined because of the crisis in international trade before World War I, and agricultural production decreased because of severe droughts. In 1917 the Republicans were defeated at the polls when José Gutiérrez Guerra (1917-20), the last Liberal president, was elected. But the long rule of the Liberals, one of the most stable periods in Bolivian history, ended when the Republicans seized the presidency in a bloodless coup in 1920.

Data as of December 1989