The memoirs are controversial in that they said that Davy Crockett did not die fighting (as is the common belief), but instead surrendered (along with his Tennessee boys) during the battle of the Alamo and was later executed.
[3] The following year he attended military college to study arithmetic, algebra, speculative geometry and plane trigonometry.
[3] When Santa Anna assumed power in 1833 de la Peña requested a commission as a lieutenant colonel in the Mexican Army.
[5] After unsuccessful attempts to be change his assignment to France, de la Peña withdrew his request and instead asked to become a part of the Federal Division of the President.
[3] By the onset of the Texas Revolution in October 1835, de la Peña had been demoted to lieutenant and was a staff officer for the elite Zapadores Battalion.
However, when the Mexican Army of Operations marched into Texas to subdue the revolution in January 1836, de la Peña was serving as an aide for Colonel Francisco Duque of the Toluca Battalion.
The Toluca Battalion joined the rest of Santa Anna's army in San Antonio on March 4, 1836, eleven days after the siege of the Texas garrison in the Alamo Mission had begun.
De la Peña remained at the front until Duque fell wounded and then returned to the rear to find General Manuel Fernández Castrillón, second-in-command of that column.
After Santa Anna was captured at the Battle of San Jacinto, de la Peña retreated with the rest of the Mexican army back to Mexico, arriving in Matamoros on June 6, 1836.
In December 1836 de la Peña was in Mexico City, where he testified in the inquiry into the actions of General Vicente Filisola during the army's retreat from Texas.
This action from both these men is surely unnatural; a general(Filisola) in the battlefield, obeying orders from his superior, who was a prisoner of the enemy.
During this time, de la Peña wrote a newspaper articles criticizing Filisola, which he signed "An Admirer of Texas".
[3] On January 7, 1838, de la Peña published a "fiery proclamation" exhorting his garrison in the District of Baroyecca to support liberty and Urrea.
It was located by researcher J. Sanchez Garza and subsequently translated into English by Carmen Perry of the Daughters of the Republic of Texas.
Imprisoned in 1838, following his involvement in the Urrea rising, De la Peña was freed in 1840 and discharged from military service.
Among those had been a man who pertained to the natural sciences, whose love of it had conducted him to Texas, and who locked himself up in the Alamo not believing it safe by his quality of foreigner, when general Santa Anna surprised [San Antonio].
In October 2001, in a Southwestern Historical Quarterly article, Dr. David B. Gracy II, and his science team, attested to the authenticity of De la Pena's work.