Frank, George, Ewin, and Harry Lacy
The documented history states that the Lacy brothers (Frank, George, Ewin, and Harry Lacy) came from Kentucky in 1858 and settled in the granite hills of Burnet County, Texas, near the modern day town of Marble Falls. They developed the Lacy dog by crossing Greyhounds, scenthounds (of unknown breed) and wild canines (of some species). There is much debate about which wild canine cross was used in developing the Lacy breed. I have no idea exactly what mix of dogs were used by the Lacy brothers to establish their foundation stock and I doubt that a DNA test could answer that either.
If your dog howls at the moon in tune with the coyotes, then your dog might be a Lacy.
Lacy Dog Working History
It is pretty clear that a major component of the working history of Lacys was herding. Lacys are a head end herding dog. They tend to seek the front end or head of their subjects and bay them or hold them in place.
This type of herding dog is very effective when rounding up wild or semi-wild livestock, and this is consistent with requirements for managing range livestock. In the 19th century in Texas and the Southwest, livestock was allowed to range in open country that had much less fencing than it does today.