Born in Lumpkin County, Georgia, in 1830, William B. Fleming came to Texas before 1850, where he enlisted in Company C of the Texas Rangers Mounted Volunteers and later served in the Confederate Army during the Civil War. After the war, he moved to Gonzales County and, in partnership with Charles Erasmus Littlefield in 1871, purchased land on the south bank of the Guadalupe River. There Fleming erected a dog run-style cabin of black walnut logs, whose remnants can still be found. He purchased his first horse, known as "Old Billy," and used him to breed a line of quarter horses known as "Billys," prized by cowboys, rodeo performers, and racing enthusiasts, making Fleming one of the premier horse breeders of his day.