Sam was created by James Robinson and was introduced as Alan Scott's boyfriend. He first appeared after the DC relaunch of 2011 and only existed on Earth-2.
Not much is known about the past of Sam and Alan. They were openly gay and dated each other. After Alan arrived in Hong Kong Sam was waiting there for him. He planned a romantic date with him at the Lodge Hotel outside of the city. They traveled with the Bullet Train and that's where Alan ask Sam to marry him. Right before Sam could give an answer, the train crashed and Sam died.
It was later revealed that Sam acted as a sort of whistleblower to Terry Sloane and in retaliation, the train crash was planned. After his "death", Sam became the Avatar of The White to complement Alan in his new role as Avatar of The Green.