Theodore Bagwell's gang, was a white supremacist group who had multiple branches, one of which was located at at Fox River. The branch of AFP in Fox River was lead by Theodore Bagwell. They were one of the most prominent and influential gangs within the prison. The gang was in a race-related rivalry with Benjamin Franklin's gang, which was also responsible for the Race War that occured. Theodore Bagwell, the leader of the group, was beaten up by Abruzzi's mobsters. Because of this, the gang began a vendetta against Abruzzi. Which eventually led to his throat being slashed.
Their members are generally vicous fighters because they don't hesitate to pull out a knife in a hand to hand fighting. It's unknown what became of gang after the escape of their leader T-Bag, but it is implied that the gang was once again under the leadership of Bagwell after his return to Fox River.
T-Bag was very interested in his Michael in their very first meeting. However, until Maytag died, he attempted to kill him, but failed. Since then, he didn't want Michael in his gang.
Lechero was rejected in his group, so that he could safely escape from Sona. Lechero was killed by T-Bag and so was money brought inside, so that everyone could escape.