William M. Harrison, Confederate officer, planter, and legislator, was born on April 26, 1819, in Christian, Kentucky, to John and Elizabeth (McClanahan) Harrison. Later that year, his family emigrated from Kentucky, where John was engaged in distilling, and settled in Howard County, Missouri. Raised on a farm near what is now Glasgow, Missouri, William was educated in the common schools and left home at age sixteen in favor of a position in his brother James's store in Hempstead County, Arkansas.
In the fall of 1836 William Harrison established his own small mercantile in the disputed territory which would soon become Red River County, Texas. He later settled down in the county seat of Clarksville, Texas, in 1841 and purchased a plantation there in 1849. On July 1, 1845, Harrison married Elizabeth Shields, the daughter of a former congressman from Tennessee. Elizabeth died in 1853, and William married Elizabeth Ann Epperson in 1855. William M. Harrison had nine children in all—three from his first marriage and six from the second. By the time war broke out, Harrison had reportedly accumulated a personal fortune of around $150,000, much of it in slaves or in debts owed to the mercantile.
Although he had opposed secession, he enlisted in the Confederate Army on October 9, 1861, and was appointed captain and quartermaster of what would become the Ninth Texas Infantry. Captain Harrison survived illness and the battle of Shiloh with the Ninth Texas, but he resigned his commission following the army's retreat to Corinth, Mississippi, in late April 1862. Harrison spent the remainder of the war on his plantation and served a term in the legislature as a representative of Red River County.
Following the Confederate surrender, Harrison sold his plantation, and with his partner, J.W. Russell, established a "warehouse[ing], wholesale grocery and commission business." In March of 1871 William M. Harrison was elected the first president of the National Bank of Jefferson. Soon after, he was also named a president of the nascent East Line and Red River Railroad, which was acquired by Jay Gould in June of 1881. By this time Harrison had once again accumulated a sizable personal fortune in land, stock, and residential and commercial properties.
Although Harrison was "reared as an ardent Henry Clay Whig" he was a member of the Democratic Party after the war. He was also long-time Mason, taking chapter and council degrees and admitted as a member of the Legion of Honor. In addition, William M. Harrison and much of his family were members of the Cumberland Presbyterian church. He died on September 16, 1894, at Eureka Springs, Arkansas.