The Underground Railroad to Mexico
In 1829 the Mexican government banned slavery, triggering a chain of events which led to the Texas Revolution in 1836. The Republic of Texas endorsed the institution of slavery and when Texas entered the Union it was as a slave state. Following the enactment of the Fugitive Slave Law in 1850, American diplomats lobbied the Mexican government to enact laws which would allow American slave owners to cross the Mexican border to recover fugitive slaves. The Mexicans refused, and also refused to require Mexican citizens to detain American slaves who had fled from their owners. In the view of the Mexican government, they were free.
Nonetheless slave catchers and bounty hunters crossed the Mexican border in pursuit of slaves which escaped to Mexico via an Underground Railroad which developed in Texas while it was still a republic. Mexico never officially recognized the Republic of Texas and thus no treaty regarding the escaped slaves was attainable. Mexican authorities who encountered the Texans crossing the border arrested them, allowing the slaves to go free. That situation continued after Texas became a state, as Mexico’s official position was that the slave catchers and bounty hunters had entered Mexico illegally. Mexico actively assisted the escape of many slaves.
The southbound Underground Railroad operated in the same manner as its more famous northern cousins, with safe houses known as stations, guides called conductors, and ran through Texas, Arkansas, and Louisiana. The long border across the Rio Grande was patrolled, but its sheer length ensured opportunities to cross, which were monitored by Texan and Mexican opponents to slavery. Blacks arriving in Mexico were all but forced by circumstances to settle in segregated communities, separated by culture and language, but gradually assimilated into Mexican culture. The Roman Catholic Church provided sanctuaries, as did Mexican citizens.
Until the election of 1860, when secession loomed dependent on the results, the southern dominated Congress debated actions against the Mexican government for allowing escaped slaves safe haven within the borders of Mexico. The exact number of slaves which escaped to Mexico is unknown, but the amount of protests by both the federal government and the state of Texas to the Mexican government indicates it was high enough to be a major financial issue. At the same time that escaping slaves were being helped to Mexico, slave smugglers were bringing black slaves from the Caribbean to Texas by smuggling them through Mexico.
The Underground Railroad which ran to the south was neither as well organized nor as well-known as those of the northern states, and is mostly forgotten today. It was not the first southbound route to escape slavery, in the early 1800s slaves in Georgia and Alabama and even as far away as the Carolinas fled to the south to reach freedom in what was then Spanish Florida. Most of the slaves who fled to Mexico never returned to the United States. Following the American Civil War many Mexicans fled to the United States, escaping the French intervention in Mexico, and creating issues regarding Mexican immigration which are still debated.