From the FX press release:
Fans of American Horror Story got a Halloween treat today from FX as the network placed a second-season order of 13 episodes from Twentieth Century Fox Television, announced John Landgraf, President and General Manager, FX Networks.
American Horror Story, created by producers Ryan Murphy and Brad Falchuk, is the eighth FX drama series to earn a second season order. Nine all-new episodes of AHS remain in the first season airing Wednesdays at 10:00 PM E/P, with the final two episodes airing December 21.
“It’s one thing to have the ambition and guts to reinvent a genre in a way that makes it captivatingly fresh for a broad audience – it’s something else entirely to have the craft to back that ambition up,” said Landgraf. “Ryan Murphy and Brad Falchuk have hit the trifecta with Nip/Tuck, Glee and now American Horror Story, which will be scaring FX’s viewers to death for many years to come.”