Texian Army in the context of "Ground warfare"

The Mexican–American War, also known in the United States as the Mexican War and in Mexico as the United States intervention in Mexico, (April 25, 1846 – February 2, 1848) was an invasion of Mexico by the United States. It followed the 1845 American annexation of Texas, which Mexico still considered its territory because it refused to recognize the Treaties of Velasco, signed by President Antonio López de Santa Anna after he was captured by the Texian Army during the 1836 Texas Revolution. The Republic of Texas was de facto an independent country, but most of its Anglo-American citizens who had moved from the United States to Texas after 1822 wanted to be annexed by the United States.

Sectional politics over slavery in the United States had previously prevented annexation because Texas would have been admitted as a slave state, upsetting the balance of power between Northern free states and Southern slave states. In the 1844 United States presidential election, Democrat James K. Polk was elected on a platform of expanding U.S. territory to Oregon, California (also a Mexican territory), and Texas by any means, with the 1845 annexation of Texas furthering that goal. However, the boundary between Texas and Mexico was disputed, with the Republic of Texas and the U.S. asserting it to be the Rio Grande and Mexico claiming it to be the more-northern Nueces River. Polk sent a diplomatic mission to Mexico in an attempt to buy the disputed territory, together with California and everything in between for $25 million (equivalent to $798 million in 2024), an offer the Mexican government refused. Polk then sent a group of 80 soldiers across the disputed territory to the Rio Grande, ignoring Mexican demands to withdraw. Mexican forces interpreted this as an attack and repelled the U.S. forces on April 25, 1846, a move which Polk used to convince the Congress of the United States to declare war.

The Texas Military Forces (TXMF) are the principal instrument through which the Texas Military Department (TMD) executes security policy for Texas, which has the second-largest population and border in the United States.

The Texas Military Forces have a budget of $1.851 billion as of 2023. Current forces include the Texas Army National Guard, Texas Air National Guard, and Texas State Guard of the Texas Militia. Former forces include the Texian Militia, Texian Army, Texian Navy, Texas Army, Texas Navy, and Texas Marines. It also included the Texas Rangers from their inception until 1935.

The Texian Militia was the militia forces of Texian colonists in the Mexican state of Coahuila y Tejas from 1823 to 1835 and the inaugurate force of the Texas Military. It was established by Stephen F. Austin on August 5, 1823 for defense of the Old Three Hundred colonists against the Karankawa, Comanche, and Cherokee tribes; among others. Its most notable unit, the Texas Rangers, remained in continuous service of Texas Military Forces until 1935.

The Texian Militia sparked the Texas Revolution at the Battle of Velasco and became legendary at the Battle of Gonzales (the "Lexington of Texas") which marked its transition to the Texian Army and Texian Navy. Their legend continued at the Battle of the Alamo as the only relief force to answer the To the People of Texas & All Americans in the World letter. The Texian Militia comprised 22% of the Texian Army service members who fought until the Battle of San Jacinto, helping the Texian Government win independence from the Centralist Republic of Mexico on May 14, 1836 at the Treaties of Velasco.

The Texian Navy, also known as the Revolutionary Navy and First Texas Navy, was the naval warfare branch of the Texian armed forces during the Texas Revolution. It was established by the Consultation of the Republic of Texas on November 25, 1835. Along with the Texian Army, it helped the Republic of Texas win independence from the Centralist Republic of Mexico on May 14, 1836 at the Treaties of Velasco. It was replaced by the Texas Navy on March 23, 1839.

The Texas Army, officially the Army of the Republic of Texas, was the land force branch of the Texas Military Forces during the Republic of Texas. It descended from the Texian Army, which was established in October 1835 to fight for independence from Centralist Republic of Mexico in the Texas Revolution. The Texas Army was provisionally formed by the Consultation in November 1835; however, it did not replace the Texian Army until after the Battle of San Jacinto. The Texas Army, Texas Navy, and Texas Militia were officially established on September 5, 1836, in Article II of the Constitution of the Republic of Texas. The Texas Army and Texas Navy were merged with the United States Armed Forces on February 19, 1846, after the Republic of Texas became the 28th state of America.

The Battle of the Alamo (February 23 – March 6, 1836) was a pivotal event and military engagement in the Texas Revolution. Following a 13-day siege, Mexican troops under President General Antonio López de Santa Anna reclaimed the Alamo Mission near San Antonio de Béxar (modern-day San Antonio, Texas, United States). About one hundred Texians, wanting to defy Mexican law and maintain the institution of chattel slavery in their portion of Coahuila y Tejas by seeking secession from Mexico, were garrisoned at the mission at the time, with around a hundred subsequent reinforcements led by eventual Alamo co-commanders James Bowie and William B. Travis. On February 23, approximately 1,500 Mexicans marched into San Antonio de Béxar as the first step in a campaign to retake Texas. In the early morning hours of March 6, the Mexican Army advanced on the Alamo. After repelling two attacks, the Texians were unable to fend off a third attack. As Mexican soldiers scaled the walls, most of the Texian fighters withdrew into interior buildings. Those who were unable to reach these points were slain by the Mexican cavalry as they attempted to escape. Almost all of the Texian inhabitants were killed.

Several noncombatants were sent to Gonzales to spread word of the Texian defeat. The news sparked both a strong rush to join the Texian army and a panic, known as "The Runaway Scrape", in which the Texian army, most settlers, and the government of the new, self-proclaimed but officially unrecognized Republic of Texas fled eastward toward the U.S. ahead of the advancing Mexican Army. Santa Anna's execution of surrendering soldiers during the battle inspired many Texians and Tejanos to join the Texian Army. The Texians defeated the Mexican Army at the Battle of San Jacinto, on April 21, 1836, ending the conquering of the Mexican state of Coahuila y Tejas by the newly formed Republic of Texas.

28°38′51″N 97°22′59″W / 28.6476°N 97.3830°W / 28.6476; -97.3830

The Goliad massacre was an event of the Texas Revolution that occurred on March 27, 1836, following the Battle of Refugio and the Battle of Coleto; 425–445 prisoners of war from the Texian Army of the Republic of Texas were executed by the Mexican Army in the town of Goliad, Texas. The men surrendered under the belief they would be set free within a few weeks; however, this was not to be. Despite appeals for clemency by General José de Urrea, the massacre was carried out by Lt. Colonel José Nicolás de la Portilla, under orders from General and President of Mexico Antonio Lopez de Santa Anna.