Horace Clark, college president and minister, was born on July 7, 1819, in Charleston, Massachusetts, the only son of John and Catherine (Aldrich) Clark. He was raised by his mother after his father's death in 1821. Clark served four years under his uncle, who was a captain in the merchant marine. At fourteen he was pressed into the Portuguese navy in Rio de Janeiro, but the intervention of a Captain Brown and the United States consul brought about his release. In 1836 he and his mother moved to Alton, Illinois, and he entered Shurtleff College. He moved to Georgetown College, Georgetown, Kentucky, in 1841 and completed his education. He and Martha Davis were married on March 30, 1844, in Macoupin County, Illinois.
Clark was the principal of Henry Academy, New Castle, Kentucky, from 1846 to 1850 and La Grange Collegiate Institute, La Grange, Texas, in 1851. On June 18, 1851, he accepted the position of principal at Baylor Female Department in Independence (see UNIVERSITY OF MARY HARDIN-BAYLOR). He served as secretary of the Baptist State Convention of Texas from 1856 to 1858 and in 1867, and he was corresponding secretary in 1861, 1864, 1868–70, and 1875. On September 18, 1858, he was ordained a minister by Independence Baptist Church. He resigned as principal in 1866, and during his year-long leave of absence, Baylor Female Department was organized into Baylor Female College, on September 28, 1866. Benjamin Simms Fitzgerald was named the first president of Baylor College. The following year Clark returned and was elected to replace him. He served until July 12, 1871. Later that fall, Clark opened Clark's Academy for young ladies in Houston. The school ceased to exist in seven or eight years.
About 1877 Horace Clark joined the Episcopal Church. His wife remained a Baptist. He was confirmed as a deacon in Christ Church, Houston, on November 22, 1878, where he served as assistant pastor. He was ordained to the priesthood at St. David's Church, Austin, on April 20, 1879, and accepted the rectorship of the Church of the Good Shepherd, Corpus Christi, in 1880; there he served for eighteen years. His wife died on January 9, 1896, in Corpus Christi. Clark was a Mason and served as grand chaplain of the Grand Lodge of Texas from 1876 through 1879, 1884–85, and 1901–02. He was grand chaplain of the Grand Royal Arch Chapter of Texas in 1869–70. He died on February 10, 1909, and was buried at Glennwood Cemetery, Houston. He was survived by three children.