Why did the anti-federalist believe that it was critically important for a democratic society to provide constitutional guarantees for free speech and a free press

Well most likely to have the freedom to say what you need to say, like in the news, they report on things they think they needs to be heard by the people, and the people need to talk about such an event. Like somethin' shady the government was doing, that was recently brought to light, the founding fathers wanted the press to always have the ability to bring a greater light to this. 

The  pan-african movement  was an "emotional, cultural, psychological and ideological  movement  that began among the  african  dispora in the western hemisphere, for a closer  purpose, so that  african  people could feel secure, attain political, economic as well as psychological power visa vis other races or world regions" .