McMullen's business acumen impressed the Mexican government, and in 1828 it granted him an empresario contract to establish a colony in Texas, making his one of only two officially sanctioned colonies for European settlers. Empresario contracts resembled land grants, but the actual property transfer was more complicated than an outright transfer of ownership. An empresario grant outlined an area in which an empresario could establish his settlement. Settlers could choose a plot within its boundaries, have it surveyed, and receive a title provided government officials approved the request. Because Mexico required landholders to be Roman Catholics, Catholic Irish emigrants, such as McMullen, were ideal candidates, and McMullen and his partner and stepson James McGloin traveled to New York and Philadelphia in 1829 to recruit Irish colonists. The two men returned to Texas later that year with several hundred colonists to establish the town of San Patricio on the Nueces River in 1831.
Over the next few years, McMullen managed the affairs of his newly established colony, defending it from Indians, procuring supplies, and overseeing the land-grant process. In 1833, he adopted a boy from North Carolina, who at age nine was baptized as José Antonio de Jesus in San Fernando Cathedral in San Antonio. In 1835, as Texas neared war with Mexico, McMullen's position as the de facto leader of San Patricio placed him in a position to participate as a revolutionary leader. When Texans convened the Consultation of November 1835 to deliberate the best course to take in its troubles with Mexico, McMullen won election as San Patricio's representative, and also served as a member of the General Council, Texas' provisional government, late 1835 to March, 1836.
As a member of the General Council, McMullen found himself part of a growing faction opposed to Governor Henry Smith, a farmer from Brazoria and a strong proponent of Texas independence. The disagreement began when Smith opposed the Council's decision to create a volunteer army to supplement the paid force already recruited. When the Council passed the resolution establishing the separate volunteer army despite his objections, Smith accused his opponents of dishonesty and conspiring against him. The Council retaliated by forming an investigatory committee to evaluate Smith's fitness as governor. As a member of that committee, McMullen supported its eventual censure of Smith and its recommendation to remove him from office. The recommendation was successful, and Lieutenant Governor and president of the Council, James W. Robinson, became the new governor of Texas. In turn, McMullen replaced Robinson as president pro tempore of the council. John Bower, a fellow San Patricio resident, took McMullen's former position as San Patricio's representative.
When the General Council called for the Convention of 1836 to write the Texas Declaration of Independence and the Constitution of the Republic of Texas, McMullen ran against Bower to be San Patricio's delegate at the Convention. San Patricio, which was close to Mexico and likely to suffer greatly from increased hostilities, was overwhelmingly against war with Mexico, and had supported Governor Smith during his quarrel with the General Council. Although McMullen initially appeared to win the election despite his disagreements with his constituency, Bower came to the March 4th session of the Convention to protest McMullen's election, accusing him of fraud. The merits of this accusation appeared valid, especially considering McMullen's growing unpopularity in San Patricio. The members of the Convention agreed, and Bower replaced McMullen as San Patricio's representative.
When McMullen returned to San Patricio later in 1836, he found the town reeling from the war with Mexico. After several attacks by Mexican troops and bandits, many of the settlers had fled, and those who remained needed food and farming equipment. McMullen immediately sought permission from Secretary of State Thomas J. Rusk to travel to the United States to obtain supplies for the remaining residents. He did not intend, however, to participate further in the town's recovery.
The combination of the town's misfortune and the bitterness left by his recent political scandals convinced McMullen to move on. He wrote to Mirabeau Lamar, Vice President of the Republic of Texas, explaining some of his reasons: "When I left last November…I had upwards of 1300 head of cattle, which I am informed have all been drove off by one or the other party…my books were destroyed, private arms taken and everything I had was plundered and destroyed." He then expressed his intentions to move to San Antonio, proclaiming "There is no part of the continent where nature has lavished her gifts so profusely as upon the southwest part of Texas and particularly the jurisdiction of San Antonio…The day will come when this place will be the Manchester of Texas on account of the immense water power afforded by the river." In 1837, he began selling his land in San Patricio to James McGloin, who had remained there to assist in the reconstruction efforts.
McMullen moved to San Antonio and again worked as a merchant. He moved into a house, located at the south-east corner of the present day intersection of Presa Street and Market Street, and became active in city politics, serving in a variety of capacities, sometimes simultaneously. While McMullen served as a Justice of the Peace from 1840 to 1841, Mayor John W. Smith appointed him to the city council, a position he held until 1844. He was also Judge of the Probate Court in 1843, and Chief Justice of Bexar County in 1844. His last political position seems to have been as an election judge in the 1846 elections.
Although McMullen's political career ended in 1846, some locals believe his spectral presence remains in San Antonio today. During a failed robbery attempt on January 21, 1853, an unknown assailant murdered McMullen in his home. He was buried next to his wife in San Fernando Cathedral's Campo Santo, but a local legend insists that his ghost still searches for his murderer in the Hertzberg Library, site of his Market Street home. This legend, combined with McMullen's role in the formative years of San Antonio, San Patricio, and the Republic of Texas, helps continue his legacy in San Antonio history.
Flannery, John Brendan. The Irish Texans. San Antonio: University of Texas Institute of Texan Culture, 1980.
Guliek, Charles Adams, et al., ed. The Papers of Mirabeau Buonaparte Lamar: Edited from the Original Papers in the Texas State Archives, Vol 1. Austin: Pemberton Press, 1981.
Hébert, Rachel Bluntzer. The Forgotten Colony: San Patricio de Hibernia: The History, the People and the Legends of the Irish Colony of McMullen-McGloin. Burnet: Eakim Press, 1981.
Oberste, William H. The Texas Irish Empresarios and Their Colonies: Refugio and San Patricio. Austin: Von Boeckman-Jones Co., 1973.Our Thanks to Alexander Stevens for his work.