Shadaloo
Cammy's early history is unknown; her first appearance in the Street Fighter chronology was Street Fighter Alpha 3, where she was a soulless Doll sent to assassinate Dhalsim. Dhalsim used his spiritual powers to make her self-aware, and she realized that Shadaloo was controlling her. M. Bison sent Vega to observe her. When Vega confronted her, he revealed to her that she was an "experiment" and was no longer needed. Vega intentionally lost a battle to her, and she wondered why Shadaloo wanted to destroy her, since she had never committed any altercations against them. She later encountered Juli and Juni, two other Shadaloo Dolls, who lacked the benefit of self-awareness. When Cammy confronted Bison, he told her that she was meant to become his next body, after his current physical manifestation was destroyed by his own Psycho Power. Cammy managed to break the twelve Dolls free from Shadaloo's mind control, and they confronted Bison together. He explained to Cammy that she was a clone of himself who possessed a small portion of his Psycho Power, and that if he were to die, she would die as well. Cammy fought against his psychic probing and rescued the Dolls from Bison's control with the Psycho Drive. Cammy got the Dolls out the Shadaloo base and then fell unconscious, no longer a clone, but an independent human. Vega rescued her before the base was destroyed, not wanting to allow a beautiful human to die. He deposited her on the doorstep of the British paramilitary government organization Delta Red.

Delta Red
Cammy awoke with amnesia, and Delta Red took her in. While she could not remember her past, she retained nearly all the fighting capabilities that she was imbued with during her tenure with Shadaloo. This made her a very valuable asset to the team. When the second World Warrior tournament was announced, and that Bison was part of it, Cammy felt a strange connection to him, and entered the tournament to find out. She confronted Bison, who told her that she is a copy of him, that she killed for him, that he planted her in Delta Red (but didn't count on her losing her memories), and that he had no further use for her. After Bison was defeated, her Delta Red teammates told her that she didn't need to live in the past; she had a new life to live. It is believed that Cammy still works for Delta Red, as she appeared in Final Fight: Streetwise as a pit fighter.

(Source: Wikipedia)