In 1832, following the death of his first wife, Ann Vick, he moved to Texas, first practicing medicine in San Augustine.
He subsequently moved to Nacogdoches, where he became a surveyor and later, as tensions with Mexico rose, he resumed his practice of medicine.
Irion served as a senator from Nacogdoches in the 1st Congress of the Republic of Texas, from October 4, 1836, to June 13, 1837.
In wooing her, Houston had used Irion, his Secretary of State in the Republic of Texas, to carry messages between her and himself.
When Irion understood that she was definitely not interested in marrying Houston, he persuaded her to accept his proposal of marriage.