A few years after his return to Tennessee he moved from Williamson to Hardeman County. In the fall of 1835 he and his brothers Thomas Jones and Blackstone Hardeman and his sister Julia Ann Bacon, together with their families, numbering about twenty-five people in all, moved to Texas. Bailey and several other members of the family quickly joined the independence movement. Bailey's first involvement was to help secure an eighteen-pound cannon at Dimmitt's Landing near the mouth of the Lavaca River and haul it to San Antonio, an action that encouraged Gen. Martín Perfecto de Cos to surrender his forces, on December 10, 1835. On November 28, while Hardeman was on the artillery assignment, the General Council of the provisional government appointed him to serve on a commission to organize the militia of Matagorda Municipality.
After this, Hardeman's activities shifted from the military to the political arena. He was elected a representative from Matagorda to the convention at work on the Texas Declaration of Independence. He arrived at Washington-on-the-Brazos on March 1, 1836, and was selected to serve on the five-member drafting committee of the declaration. After the convention approved the document, Bailey, along with two other members of the committee, was appointed to a twenty-one-member committee to draw up a constitution for the Republic of Texas. The resulting Constitution was approved in mid-March. Hardeman performed several other services for the convention, including membership on the militia and tariff-payment committees. Although he requested to be excused in order to rejoin the military forces, he was persuaded to assume other political duties. The delegates elected him secretary of the treasury. Concurrently with this position, he held the office of secretary of state when Samuel P. Carson left for the United States on April 2-3, 1836.
After the fall of the Alamo, Hardeman fled eastward with other cabinet members as the ad interim government moved from Washington to Harrisburg, and from Harrisburg to Galveston Island, in advance of approaching Mexican troops. The group reached Galveston in safety around the time of the battle of San Jacinto; after the Texas victory, Hardeman left the island to deliver supplies to the soldiers of the republic. As acting secretary of state he negotiated and signed two treaties, an open document honorably ending the war and providing for removal of Mexican soldiers from Texas, and a secret agreement in which Mexican general Antonio López de Santa Anna promised diplomatic recognition of the new republic. Hardeman was then appointed to go to Mexico City in order to help secure ratification of the open treaty.
His service to the republic was cut short by his death from congestive fever, probably on September 25, 1836, at his Matagorda County home on Caney Creek. He was buried there, but in 1936 his remains were moved to the State Cemetery in Austin. Bailey was survived by his wife and four children. A daughter had died at the age of eight in Hardeman County, Tennessee. Hardeman County, Texas, was named for Bailey and Thomas Jones Hardeman. Source
Texas State Cemetery