Several years ago Dr Garrett Sandford headed for a sleep research project at UCLA. Sandford used a "Dream Monster" machine he had invented that enabled him to "read" the dreams of participants in the project as they slept.
Near the end of the project, Sandford was abruptly summoned to Washington DC where he learned that the president of the United States had been trapped in a coma-like sleeping state for nearly 48 hours.
Nothing known to medical science had been able to awaken him. Somehow, something within the president's dream was preventing him from wakening and the only hope of saving him was "Project Sandman." Sanford's Dream MonDritor had also been brought to Washington and linked to experimental aparatus, which, it was hoped, would enable a man to be projected physically into the Dream Dimension, a plane of existence on which what people see in dreams actually exists. Sanford agreed to be the one to travel into the Dream Dimension.
Within the Dream Dimension, Sanford gained superhuman powers, which he used to defeat a nightmare monster that held the president's dream-self captive. Sandford's victory enabled the President to wake up from his dream.
However, there was no known means of bringing Sandford back from the Dream Dimension. The government sent the Dream Monitor into the Dream Dimension, and Sandford decided to use it to help humanity. He named himself the Sandman after the project and the 1940's costumed hero whose secret ID was Wesley Dodds.
The Sandman established a base called the Dream Dome. He learned how to return to Earth by using a "Dream Ejector Tube" to send him through the "Dream Stream," the border between the Dream Dimension and Earth. However, the Sandman can only remain on Earth for an hour at a time. The Sandman is aided by two inhuman beings, Brute and Glob, who can give people nightmares. (The master of nightmares in the Nightmare Wizard, who also lives in the Dream Dimension). The Nightmare Wizard can create very extreme nightmares that can scare children to death.
The Sandman's main concern is to prevent creatures of nightmare from entering the world of reality on Earth and carries a pouch of dream dust.
Dr. Sanford meets Wonder Woman and attempts to romance her even though she has accepted Steve Trevor's proposal of marraige. He also encounters Hippolyta Trevor, who would marry Sandford's successor and be the mother of Daniel Hall.
He would become an honorary member of the Justice League when they battled Doctor Destiny.
Sandford would later go insane due to his time in the Dream Dimension and committed suicide. It was later revealed Dr. Sandford committed suicide years ago. This would explain why Sandfords likeness has been used by Hector Hall and his son Daniel. Daniel retires the costume and likeness after he captures Brute and Glob.