mixed race black man) formally abolished slavery in Mexico. Freedom seekers from Southern plantations in the Deep South, particularly from Louisiana, Mississippi and Texas, escaped slavery and headed for Mexico. At that time, Texas was part of Mexico. The Texas Revolution, initiated in part to legalize slavery, resulted in the formation of the Republic of Texas in 1836. Following the Battle of San Jacinto, there were some enslaved people who withdrew from the Houston area with the Mexican army, seeing the troops as a means to escape slavery. When Texas joined the Union in 1845, it was a slave state and the Rio Grande became the international border with Mexico. Pressure between free and slave states deepened as Mexico abolished slavery in 1837 and western states joined the Union as free states. As more free states were added to the Union, the lesser the influence of slave state representatives in Congress. Slave states and slave hunters The Southern Underground Railroad went through slave states, lacking the abolitionist societies and the organized system of the north. People who spoke out against slavery were subject to mobs, physical assault, and being hanged. There were slave catchers who looked for runaway slaves. There were never more than a few hundred free blacks in Texas, which meant that free blacks did not feel safe in the state. The network to freedom was informal, random, and dangerous. U.S. military forts, established along the Rio Grande border during the Mexican–American War of the 1840s, captured and returned fleeing enslaved people to their slaveholders. The Fugitive Slave Act of 1850 made it a criminal act to aid fleeing escaping enslaved people in free states. Similarly, the United States government wanted to enact a treaty with Mexico so that they would help capture and return bonds-people. Mexico, however, continued their practice to allow anyone that crossed their borders to be free. Slave catchers continued to cross the southern border into Mexico and illegally capture black people and return them to slavery. A group of slave hunters became the Texas Rangers. Routes Thousands of freedom seekers traveled along a network from the southern United States to Texas and ultimately Mexico. Southern enslaved people generally traveled across "unforgiving country" on foot or horseback while pursued by lawmen and slave hunters. Some stowed away on ferries bound for a Mexican port from New Orleans, Louisiana and Galveston, Texas. There were some