During the 1829-39 presidency of Marshal Andrés de Santa Cruz, Bolivia enjoyed the most successful period of its early history with significant social and economic reforms.

Plagued by a vicious economic and political crisis, Bolivia's weakness was further demonstrated during the War of the Pacific (1879–1883), when it lost access to the ocean and the nitrate rich fields to Chile.

The overthrow of the Bourbon Dynasty and the placement of Joseph Bonaparte on the Spanish throne tested the loyalty of the local elites in Upper Peru, who were suddenly confronted with several conflicting authorities.

While some liberals eagerly welcomed the reforms of colonial rule promised by Joseph Bonaparte, others supported the claims of Carlota, Ferdinand's sister, who governed Brazil with her husband, Prince Regent John of Portugal, and many radical criollos (persons of pure Spanish descent born in the New World) wanted independence for Upper Peru.

[1] On July 16, 1809, Pedro Domingo Murillo led another revolt by criollos and mestizos (those of mixed European and Indian ancestry) in La Paz and proclaimed an independent state in Upper Peru in the name of Ferdinand VII.

After 1820 the Conservative Party criollos supported General Pedro Antonio de Olañeta, a Charcas native, who refused to accept the measures by the Spanish Cortes (legislature) to conciliate the colonies after the liberal revolution in Spain.

Olañeta, convinced that these measures threatened royal authority, refused to join the royalist forces or the rebel armies under the command of Simón Bolívar and Antonio José de Sucre.

Sucre reformed the existing tax structure to finance public expenditures and tried to revive silver mining by attracting foreign capital and technology.

Despite the fall of his government, Sucre's policies formed the basis for the following ten-year rule of Andrés de Santa Cruz y Calahumana (1829–39), the first native-born president, who was sworn into office in May 1829 after a series of short-term rulers.

Gamarra was killed in November 1841 near La Paz in the Battle of Ingavi; after the victory, Bolivia invaded Perú, and several fronts of struggle were opened in the Peruvian south.

In the district of Locumba–Tacna, a column between Peruvian soldiers and peasants defeated a Bolivian regiment in the so-called Battle of Los Altos de Chipe (Locumba).

On January 7, 1842, during the Battle of Tarapacá [es], Peruvian militias formed by the commander Juan Buendía defeated a detachment led by Colonel José María García, who died in the confrontation.

During his presidency, mining output increased because of technological innovations, such as the steam engine, and the discovery of huge nitrate deposits in the Atacama Desert (in present-day Chile).

Hoping to improve the economy by opening up the country to foreigners, Melgarejo signed a series of free trade treaties with Chile and Peru.

In an 1867 treaty with Empire of Brazil to secure water rights to the Atlantic Ocean, he ceded 102,400 square kilometers of territory, hoping to break Bolivia's isolation.

Under their rule, Bolivia opened the port of Mollendo, reducing the country's isolation by connecting the Altiplano by train and steamship on Lake Titicaca to the Pacific coast.

Hoping to gather the support of nationalist Bolivians to strengthen his internal position, Daza involved his country in the disastrous War of the Pacific.

In 1874, Chile agreed to fix the border at a latitude of 24° south in return for Bolivia's promise not to increase taxes on Chilean nitrate enterprises for twenty-five years.

On December 27, 1879, a coup led by Colonel Eliodoro Camacho overthrew Daza, who fled to Europe with a sizable portion of Bolivia's treasury.

Silver mining entrepreneurs, who had become the most important economic group in the country, created the Conservative Party (Partido Conservador) led by Mariano Baptista, a vocal opponent of the War of the Pacific.

Conservatives favored reaching a quick peace settlement with Chile, including a financial indemnity for the lost territories and enabling Bolivia to construct a railroad for continued mining exports.

General Campero completed his legal term in office and presided over elections of 1884 that brought to power Gregorio Pacheco (1884–88), leader of the Democratic Party and one of Bolivia's richest mine owners.

[7] Under the Conservatives, the high world price of silver and increased production of copper, lead, zinc, and tin combined to create a period of relative prosperity.

Through diplomatic channels in 1909, it lost the basin of the Madre de Dios River and the territory of the Purus in the Amazon, yielding 250,000 km2 to Peru[9] The Federal Revolution differed from previous revolts in Bolivia in that Indian peasants actively participated in the fighting.

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.

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.

[8] Because taxes and fees from tin production were critically important to national revenues, Patiño, Aramayo, and Hochschild exercised considerable influence over government policy.

Bolivia's First National Congress of Workers met in La Paz in 1912, and the mining centers witnessed an increasing number of strikes in the following years.

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.

The rule of the Liberals, one of the most stable periods in Bolivian history, ended when the Republicans led by Bautista Saavedra seized the presidency in a bloodless coup of 1920.