Dimmitt and a few of his men left Goliad in early December to join the siege of Bexar and participated in the final battle which forced Cos to surrender.
In honor of their new aim, Dimmitt designed a second flag, a white background with a severed, bloody arm holding a sword.
The new Texian Army commanders and the provisional government were angry with the premature declaration and instructed Dimmitt to lower his flag.
He and his volunteers eventually joined the Texian Army, under Sam Houston on April 22, the day after the battle of San Jacinto.
For several years he lived in San Antonio de Bexar, where he worked as a commissary contractor for the Mexican soldiers garrisoned at the Alamo Mission.
After marrying Maria Luisa Lazo, Dimmitt settled near Guadalupe Victoria in the colony of Martín De León.
As early as September 18] Dimmitt, along with James Fannin and John Linn, had begun advocating a plan to seize Cos at either Copano or Goliad.
The plan was abandoned in late September as instead colonists flocked to Gonzales, where the Texas Revolution officially began on October 2.
[3] On October 6, members of the Texian militia in Matagorda, under George Collinsworth, decided to implement Dimmitt's plan and march on Presidio La Bahía in Goliad.
His design began with the green, white, and red tricolor of the Mexican flag, but replaced the central eagle with the words "Constitution of 1824", or sometimes just "1824".
[5] In a letter to Austin dated October 15, Dimmitt proposed an attack on Fort Lipantitlán, whose capture would "secure the frontier, provide a vital station for defense, create instability among the centralists, and encourage Mexican federalists".
[6] Austin did not order an assault, and an angry Dimmitt wrote on October 27 that Williams and Toole had been sent to Matamoros, beyond the reach of the Texians.
Dimmitt chose to act without orders from Austin and on October 31 sent Adjutant Ira Westover with a force of 35 men to take Fort Lipantitlán.
[9] Without an easy means of communication with Matamoros in the Mexican interior, Cos was unable to quickly request or receive reinforcements or supplies.
[11] Dimmitt was temporarily relieved of his command on November 18, 1835, after an incident involving Agustín Viesca, the deposed governor of Coahuila y Tejas.
[12] Many members of the government, as well as acting army commanders Frank W. Johnson and James Grant[13] demanded that the flag be lowered.
[1] About January 24, Dimmitt and thirty volunteers arrived in San Antonio de Bexar to reinforce the Texians garrisoned at the Alamo.
Travis assigned one of his men to stand lookout in the bell tower of the San Fernando Church and warn him if Mexican soldiers appeared.
[14] The Texians were completely unprepared for the arrival of the Mexican army, and scrambled about to gather food and supplies for the anticipated siege.
[16] By late afternoon Bexar was completely occupied by about 1500 Mexican troops, who quickly raised a blood-red flag signifying "No Quarter" above the San Fernando Church.
When Mexican General Jose de Urrea prepared to enter Victoria on March 21, Dimmitt and his men joined the settlers in fleeing east.
The post was about 15 miles (24 km) from one that had long been operated by William P. Aubrey and Henry Kinney, who dealt in contraband with Mexican troops.
Aubrey and Kinney were eventually arrested and charged with treason, but were acquitted on August 22, probably due to pressure from Texas President Mirabeau B. Lamar.
The request was unsuccessful; the Mexican government was still angry with Dimmitt for his role in the Goliad Declaration of Independence and had no intention of releasing him.