In July 1835 Dancy married Evalina Rhodes. After her death the following summer he decided to move to Texas. On December 28, 1836, he and Francis R. Lubbock arrived at Velasco on the schooner Corolla. Dancy became a citizen of Texas on January 13, 1837, before Judge Robert M. Williamson. He traveled throughout the republic and in 1838 purchased 640 acres in Fayette County. He introduced long-staple cotton to Texas and developed the first hydraulic ram in the state to provide irrigation for his plantation.
In 1841 he was elected Fayette County representative to the Sixth Congress of the Republic of Texas. He later served in the Senate of the Second and Fourth state legislatures (1847-48 and 1851-53) and in the House of the Sixth Legislature (1855-56). He was considered an eloquent but long-winded speaker. Dancy ran for governor as a Democrat in 1853 but placed last in a field of six candidates led by Elisha M. Pease. In February 1861 he was a delegate to the Secession Convention. His early advocacy of railroad development earned him the nickname "Father of Texas Railroads." During his first legislative term he advocated annexing California and constructing a railroad to connect the West Coast to Texas. He helped secure charters for the Harrisburg Railroad and Trading Company and the Buffalo Bayou, Brazos and Colorado Railway; he became a vice president of the latter and in 1866 transferred it to the Southern Pacific. In 1850 Dancy proposed using public lands to finance railroad construction.
He maintained a law practice in La Grange and was a developer of Colorado City, the site chosen by the legislature in 1838 for the new capital but vetoed by President Sam Houston. Dancy was a member of the Texas Monumental Committee, formed to raise funds for a monument to men killed during the Mier Expedition and Dawson Massacre, and edited the committee's newspaper, the Texas Monument, from July 1850 to June 1851. He was a founding trustee of Rutersville College. During the Mexican invasions of 1842, Dancy served in the First Regiment of Texas Mounted Volunteers under John Coffee Hays. From May to July 1847 he served as a private in a spy company of Texas mounted volunteers commanded by Benjamin McCulloch. He also fought in Indian skirmishes. He married Lucy Ann Nowlin of Austin on October 25, 1849. They had a son and five daughters. Dancy died in La Grange on February 13, 1866, and was buried in La Grange Cemetery.
29° 54.625, -096° 52.090
Old La Grange City Cemetery