Persuading the weary Texians not to back down during the Siege of Béxar, Milam was killed in action while leading an assault into the city that eventually resulted in the Mexican Army's surrender.

[2] In New Orleans in 1819, Milam met José Félix Trespalacios and James Long, who intended to lead a filibustering expedition to Texas to help Mexican revolutionaries in their ongoing fight for independence from Spain.

While Long marched to Presidio La Bahía, Milam and Trespalacios traveled to Veracruz and Mexico City; both parties met a hostile reception and were quickly imprisoned.

[1][2] In 1825, Milam and Arthur G. Wavell, an English general in the Mexican Army, became partners in a silver mine operation in Nuevo León.

In 1829, Milam sought to organize a new mining company in partnership with David G. Burnet, but their efforts failed due to a lack of funds.

Milam and Wavell's empresarial efforts also failed when their contract was canceled by the Mexican government for an insufficient supply of new citizens for their colony in Texas, following a new law passed in 1830.

However, before Milam could leave the city, word arrived that Mexican President Antonio López de Santa Anna had overthrown the representative federal government and established a dictatorship.

[2] By chance, Milam encountered a company of Texian soldiers commanded by George Collinsworth, from whom he learned of the movement for independence in Texas.

He then joined the main Texian Army in its attempt to expel all Mexican forces from Texas by capturing San Antonio in the ongoing Siege of Béxar.

While returning from a scouting mission in the southwest on December 4, 1835, Milam learned that a majority of the army was considering retreating into winter quarters instead of continuing on with the planned attack on San Antonio.

Standing with Johnson and Henry Karnes near the Veramendi house, Milam had been trying to observe the San Fernando church tower with a field telescope given to him by Stephen F. Austin when he was shot in the head by a Mexican rifleman and killed instantly.