The Conservative Party (Partido Conservador) ruled in Nicaragua from 1857 to 1893, a period of relative economic progress and prosperity sometimes referred to as the "Thirty Years." A railroad system connecting the western part of Nicaragua with the port of Corinto on the Pacific coast was built, and roads and telegraph lines were extended. Exports of agricultural products also increased during this period. Coffee as an export commodity grew between the 1850s and the 1870s, and by 1890 coffee had become the nation's principal export. Toward the end of the 1800s, Nicaragua experienced dramatic economic growth because of the growing demand for coffee and bananas in the international market. The local economic elites were divided between the established cattle raisers and small growers and the new coffee-producers sector. Disputes about national economic policy arose between these powerful elites. Revealing their sympathies, the ruling conservatives passed laws favoring cheap labor that benefited mostly coffee planters.

The period of relative peace came to an end in 1891 when Roberto Sacasa, who had succeeded to the presidency in 1889 after the death of the elected incumbent, was elected to a term of his own. Although a conservative, Sacasa was from León, not Granada, and his election produced a split within the ruling Conservative Party. When Sacasa attempted to retain power after the March 1893 end of his term, the liberals, led by General José Santos Zelaya, quickly took advantage of the division within conservative ranks.

A revolt began in April 1893 when a coalition of liberals and dissident conservatives ousted Sacasa and installed another conservative in office. An effort was made to share power with the liberals, but this coalition soon proved unworkable. In July, Zelaya's liberal supporters resigned from the government and launched another revolt, which soon proved successful. A constitutional convention was hurriedly called, and a new constitution incorporating anticlerical provisions, limitations on foreigners' rights to claim diplomatic protection, and abolition of the death penalty was adopted. Zelaya was confirmed as president, a post he would retain until 1909.

Zelaya's rule proved to be to be one of the most controversial periods in Nicaraguan history. Zelaya was a ruthless dictator who managed to stay in power for sixteen years despite foreign and domestic opposition. Nevertheless, he was responsible for the creation of a professional army and the growth of strong nationalist feelings.

Zelaya opened the country to foreign investment, expanded coffee production, and boosted banana exports. His government promoted internal development and modernized Nicaragua's infrastructure. During his tenure, new roads and seaport facilities were constructed, railroad lines were extended, and many government buildings and schools were built. The proliferation of United States companies in Nicaragua grew to the point that, by the early 1900s, United States firms controlled most of the production of coffee, bananas, gold, and lumber.

Zelaya's admin895 inistration was also responsible for an agreement ending the Nicaraguan dispute with Britain over sovereignty of the Caribbean coast. Aided by the mediation of the United States and strong support from the other Central American republics, control over the Caribbean coast region was finally awarded to Nicaragua in 1894. Sovereignty did not bring the government in Managua control over this region however the Caribbean coast remained culturally separate and inaccessible to the western part of the country. Although his reputation was boosted by resolution of the centuries-old dispute with Britain, Zelaya was regarded with suspicion abroad. His imperialistic ambitions in Central America, as well as his vocal rebukes of United States intervention and influence in Central America, won him little support. Zelaya's nationalist anti-United States stance drove him to call upon the Germans and Japanese to compete with the United States for rights to a canal route. Opposition to these schemes from the conservative faction, mostly landowners, led Zelaya to increase repression. In 1903 a major conservative rebellion, led by Emiliano Chamorro Vargas, broke out. Another uprising in 1909, this time aided by British money and the United States marines, was successful in driving Zelaya from power.

Data as of December 1993