Do we know that this was the action of an "algorithmic censor"? I mean, one of the automated censors? My impression was that Facebook still has many human censors [0] in its employ, many of them outsourced in non-U.S. countries. It's possible that a human user flagged this Declaration of Independence post, and a human censor approved the flagging/censoring of it.
Yes, I know that "algorithm", broadly defined, could include a process in which a human user flags something for a human censor, but that's not how "algorithmic censors" is typically used in this context.
[0] http://www.latimes.com/business/technology/la-fi-tn-facebook...