Slaughter was a ranching pioneer, banker, and philanthropist, born on February 9, 1837, in Sabine County, Texas. He was a rancher and cattleman throughout his life. He also served with the Texas Rangers. Slaughter was with the expedition that freed Cynthia Ann Parker from the Comanches. Often referred to as the “Cattle King of Texas,” Slaughter became one of the country’s largest individual owners of cattle and land (over a million acres and 40,000 cattle by 1906.) He was the largest individual taxpayer in Texas for years.