Elijah Sterling Clack Robertson, lawyer and soldier, son of Frances King and empresario Sterling Clack Robertson, was born in Giles County, Tennessee, on August 23, 1820. He came to Texas in December 1832 and entered school in San Antonio, where he learned to read and speak Spanish. From the fall of 1834 until the fall of 1835 he worked as Spanish clerk in the land office of Robertson's colony. In 1835–36 Robertson was a member of a company of Texas Rangers engaged in repelling Indian raids. From April 1837 until May 1839 Robertson attended Jackson College in Maury County, Tennessee. On his return to Texas he became a clerk in the post office department of the Republic of Texas. In June 1839 he became chief clerk, and on October 9, 1839, he was appointed acting postmaster general, serving until January 8, 1840. He served as assistant secretary of the Senate during the Sixth Congress (1841–42). He also served with a company of volunteers that pursued Rafael Vásquez to the Rio Grande. On August 5, 1844, President Sam Houston commissioned Robertson colonel of the Second Regiment, First Brigade, Militia of the Republic of Texas. In May 1845 Robertson went to Cincinnati, Texas, taking along in his saddlebags a copy of Blackstone. By clerking in a store during the day and reading law at night, he received his license that fall to practice law in the courts of Texas. He married Eliza Hamer Robertson, his cousin and the daughter of James Randolph Robertson, on July 29, 1846. They had three children. She died on March 25, 1852, and on November 8, 1852, he married Mary Elizabeth Dickey. They had twelve children.
In 1848 Robertson had been appointed translator of Spanish deeds in the General Land Office in Austin. In 1854 he began construction of his home in Salado, which was still standing in the 1990s. He was elected chief justice of Bell County in 1858 and was commissioned brigadier general of the Twenty-seventh Brigade, Texas State Troops, on April 14, 1860, by Governor Houston. As a delegate to the Secession Convention in 1861, he signed the secession ordinance. He was appointed aide-de-camp to Gen. Henry E. McCulloch in 1862 and served to the close of the Civil War. He was also a member of the Constitutional Convention of 1875. During Reconstruction he devoted his efforts to the building of educational enterprises and placing his business interests on a firm basis. Salado College was largely the result of his efforts. Robertson was a member of the Democratic party and the Methodist Church, South. He died at Salado on October 8, 1879, and was buried in the family cemetery near his home.