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.
Texas Dog Manual
If your dog howls at the moon in tune with the coyotes,
then your dog might be a lacy.