I don't think the selling of Anna happens before the baptism. The baptism seems to follow not too long after the events at Wounded Knee.
I think the baptism is the starting point for the whole story, a singular "constant" that spins off into infinite variations (the other Bioshock worlds). What the other variations there are, outside of the two main timelines we follow in the game, are not specified, but are fun to speculate about. In one timeline, though, we know that Dewitt is baptized, changes his name, turns his life around to become spiritual and powerful, marries an infertile woman, and meets Ms. Lutece. In the other, he is not baptized, then goes on to have a child and sell her to Mr. Lutece when his debts get out of control.
My theory is that the reason Comstock is such a racist, patriotic tyrant is that his Born-again lifestyle has caused him to rationalize his past atrocities in the attitudes of Patriotism and racism -- he sees himself as a holy man after the baptism and subsequent induction into the religious community. Thus, a holy man surely would only have served at Wounded Knee to uphold sacred ideals and protect his country against subhuman aggressors. The player Dewitt does not become a holy man -- he throws his life away because he is unable to cope with what he did at Wounded Knee.
I think the baptism is the starting point for the whole story, a singular "constant" that spins off into infinite variations (the other Bioshock worlds). What the other variations there are, outside of the two main timelines we follow in the game, are not specified, but are fun to speculate about. In one timeline, though, we know that Dewitt is baptized, changes his name, turns his life around to become spiritual and powerful, marries an infertile woman, and meets Ms. Lutece. In the other, he is not baptized, then goes on to have a child and sell her to Mr. Lutece when his debts get out of control.
My theory is that the reason Comstock is such a racist, patriotic tyrant is that his Born-again lifestyle has caused him to rationalize his past atrocities in the attitudes of Patriotism and racism -- he sees himself as a holy man after the baptism and subsequent induction into the religious community. Thus, a holy man surely would only have served at Wounded Knee to uphold sacred ideals and protect his country against subhuman aggressors. The player Dewitt does not become a holy man -- he throws his life away because he is unable to cope with what he did at Wounded Knee.