In 1806, Burnet volunteered to serve the unsuccessful filibustering expeditions led by General Francisco de Miranda for the independence of Venezuela from Spain.

After Sam Houston's victory at the Battle of San Jacinto, Burnet took custody of Mexican General Antonio López de Santa Anna and negotiated the Treaties of Velasco.

Many Texans were infuriated that the treaty allowed Santa Anna to escape execution, and some called for Burnet's arrest for treason.

When the firm suffered financial difficulty, Burnet gave his entire personal inheritance, $1,300 (equivalent to $26,000 in 2023), to try to save the company.

[3] In 1806, Burnet volunteered to serve the unsuccessful filibustering expeditions led by general Francisco de Miranda for the independence of Venezuela from Spain rule.

A doctor diagnosed him with tuberculosis and suggested he move to Texas, then a part of Mexico to recuperate in the dry air.

A Comanche tribe came to his aid when he fell off of his horse by the Colorado River, and he lived with them for two years until he made a full recovery.

[citation needed] In Cincinnati, Burnet wrote a series of articles for the Literary Gazette detailing his time with the Native Americans.

He practiced law for several years but returned to Texas after hearing of Stephen F. Austin's thriving colony for Anglos.

[6] After a failed venture with Milam, the Western Colonization and Mining Company, in 1827, Burnet traveled with Lorenzo de Zavala and Joseph Vehlein to the Coahuila y Tejas state capitol, Saltillo.

[7] Eager to return to Texas, Burnet and his new wife chartered the ship Call and brought a steam engine to operate a sawmill.

A storm grounded the ship along Bolivar Point, and, to lighten the load, they were forced to discard all of Hannah's furniture and her hope chest.

Under Mexican law, Burnet was entitled to an extra land grant because his sawmill provided a needed public service.

[7] Burnet was a delegate to the Convention of 1833, where he was elected the chair of a committee that created a petition arguing that the Mexican Congress approve separate statehood for Texas.

Over the next two years, Santa Anna began consolidating his political control over the country by dissolving the Mexican Congress and disbanding state legislatures.

At the consultation, Burnet formed a provisional state government based on the 1824 Constitution of Mexico, which Santa Anna had already repudiated.

[8] Speaking privately with many of the delegates, Burnet professed that he would be willing to serve as president of a new republic, even if that made him a target of Santa Anna.

[9] One of Burnet's first acts as president was to transfer the capital of the new state from Washington-on-the-Brazos to Harrisburg, which was located nearer to the small Texas Navy at Galveston Island.

[10] Sam Houston, leading the Texan Army, also decided to strategically retreat from Gonzales after learning of the defeat at the Alamo.

On hearing of the government's flight, "Houston was pained and annoyed" and maintained it was a cowardly action that had caused a great deal of unnecessary panic.

Houston's staff "complained that the president grumbled ungraciously, was hard to please, and spent all of his time giving orders and collecting souvenirs.

In a public treaty, Santa Anna agreed to immediately cease all hostilities and withdraw his troops south of the Rio Grande.

Secretly, the men agreed that Santa Anna would "use his influence with the Mexican government to secure the recognition of Texas Independence with its southern boundary as the Rio Grande.

Burnet was part of a five-person commission to negotiate with Chief Bowl for the "peaceful" expulsion of the Cherokee tribe from their territory northwest of Nacogdoches.

[20] In December 1840, Burnet became acting president when Lamar took a leave of absence to seek medical treatment in New Orleans for an intestinal disorder.

[20] His first official act, on December 16, was to deliver an address to Congress alleging that Mexican armies were preparing to invade Texas.

Burnet wanted Congress to declare war on Mexico and to attempt to push the Texas southern boundary to the Sierra Madres.

[21] Houston questioned Burnet's honesty by accusing him of taking a $250,000 bribe from Santa Anna and calling him a "political brawler" and a "canting hypocrite.

Unable to make ends meet on their own, Burnet and his wife rented their 300 acres (1.2 km2) to another family in 1857 while they continued to live in their house.

[25] Burnet's last public service came in 1868 when he was appointed as a delegate to the Democratic National Convention, which nominated Horatio Seymour for president.