This comic's comments

Didn't you hear? Lincoln freed the slaves will free the slaves in about 1800 years. . . .
From the comments thread:

cyanocorax: So, couldn't he free both the mother and child AFTER the birth?

_w_o_o_d_: A freedman is not the same as a free man. The children of a freedman are free men.

klio: In particular it would be seen as a reasonable enough thing to do, for a man who's the father of a child by a slave he owns to free them both—make an honest woman of her, so to speak. But there was a special social status to being freeborn rather than a freedman (or freedwoman). Which in turn affected which family the freed-people belonged to, what their names were, their property rights and career possibilities, and would also come to bear on the status and family of the grandchildren. The laws governing all this mutated over time, sometimes becoming more rather than less restrictive, and pretty often getting awfully convoluted. Very very Roman.