In 1842, his family immigrated to Texas, including Howell's 3 brothers, Hardin, Edmond, and Hiram.
They all assumed leading positions in the Texas state government.
Runnels eventually married someone Martha Caroline Adams on October 1, 1859, in Harrison, Texas.
In the 1870 census, Runnels was listed as a store clerk in Boston, Texas.
Sometime in 1876, Runnels moved to Texarkana, Bowie County, Texas, where he lived for the remainder of his life.