Mexico’s revolt against the Spanish crown began on September 16, 1810, a date celebrated annually as Día de la Independencia, or Mexican Independence Day, in a climate of social and economic instability.

In an attempt to regain control over the powerful Catholic Church, the Spanish government had seized all church funds, which left the local economy in turmoil. Padre Miguel Hidalgo y Costilla issued the call for independence from the mainland city of Dolores, Guanajuato. It would take more than a decade, but Mexico would finally emerge independent from Spain in 1821.

According to the Plan de Iguala treaty, the Catholic Church would remain the dominant force in Mexico, a constitutional monarchy would rule, and mestizos and Mexican-born Spaniards would gain equal rights under the new regime. Former viceroy Agustín de Iturbide became emperor of the new republic but only for two years. In its first 30 years of independence, Mexico would weather 50 changes in government.

In 1830 the capital of Baja California moved from Loreto to La Paz following a severe hurricane, and in 1834 the last Dominican mission in Baja was established at Guadalupe, northeast of Ensenada.

The Mexican-American War

In 1833 Antonio López de Santa Anna, a powerful general who had enforced the expulsion of Spain’s troops from Mexico, seized power, revoked the Constitution of 1824, and set in motion the chain of events that would lead to independence for Texas, war with the United States, and the loss of vast territories in the north.

The United States declared war on Mexico in 1846, following a series of skirmishes over the border with the newly established U.S. state of Texas. In Baja, Mexican and U.S. forces confronted each other at Santo Tomás, Mulegé, La Paz, and San José del Cabo. Mexico City surrendered to the United States in March 1847, and the two countries signed the Treaty of Guadalupe Hidalgo in 1848, in which Mexico conceded the Rio Grande area of Texas as well as part of New Mexico and all of Alta California in exchange for US$25 million and the cancellation of all Mexican debt. The treaty moved the border between Baja California and Alta California from El Rosario to Tijuana, establishing a new international border zone.

In 1849 many Baja California residents left the peninsula to pan for gold in the California gold rush. As Baja’s population dwindled, it became a land of bandits, pirates, outlaws, and misfits.

The latter part of the 19th century brought more turbulence for Mexico. In 1853 Mexico sold Arizona and southern New Mexico to the United States for US$10 million, and American military “freebooter” William Walker invaded La Paz with 45 mercenaries and declared himself president of the Republic of Lower California. The Americans fled when he heard that Mexican troops were en route to La Paz. Walker was tried and acquitted in the United States for violating neutrality laws, but he was subsequently executed for a similar attempt in Nicaragua two years later.

The War of Reform

The Mexican people overthrew General Santa Anna in 1855, and he was replaced by a Zapotec lawyer named Benito Juárez. In 1858 a civil war called the War of Reform broke out on the mainland, with the wealth of the church at the root of the conflict. The liberals, led by Juárez, drafted a new constitution to limit the powers of the church, while the opposition seized control of Mexico City. The liberals declared victory in 1861, and Juárez became president.

The French invaded Mexico the following year, after Mexico failed to pay its debts to France. Napoleon III captured Puebla and then Mexico City, where he placed Austrian Ferdinand Maximilian as emperor of Mexico. The United States pressured France to withdraw, Maximilian was executed by a Juarista firing squad, and Juárez resumed control of the nation in 1867.

The end of the decade brought a series of reforms to strengthen the Mexican economy and its educational system. Juárez died in 1872 and his political opponent Porfirio Díaz took over, continuing the program of reform but with a much more authoritarian approach. Díaz ran the country for nearly three decades, and during this time, he improved its transportation and education systems, but at the expense of political freedom.

Foreign Investment

Díaz promoted aggressive foreign investment in Baja, selling large tracts of land to U.S. and European corporations. The peninsula’s gold- and silver-mining era began in 1878, with the arrival of the American Progreso Mining Company. In 1883 the International Company of Mexico, a joint venture among U.S., British, and Mexican investors, bought the rights to develop more than seven million hectares (18 million acres) of land south of Tijuana.

The British would build a pier and flour mill near San Quintín, but colonization efforts would end without success. A French mining company named Boleo & Cie commenced mining operations and built the town of Santa Rosalía beginning in 1885. In 1889 the discovery of gold near Ensenada triggered a rush to Santa Clara.

The Territory of Baja California was divided into two districts, north and south, at the 28th parallel, in 1885.