I made a powerpoint presentation on a lot of aspects of the Berlin wall 1961-1989. This powerpoint presentation consists of pictures, graphics and maps with only a bit of text. This powerpoint can be used to illustrate your story about the relevance and impact of the Berlin wall:
A multimedia site from the German magazine Der Speigel, with pictures of the building of the Berlin Wall, as well as some then-and-now comparison pictures.
A collection of nearly 3000 high-resolution World War II propaganda posters maintained by an American writer living in Berlin. Wonder what his German mates think?
In Who Abolished Slavery? Slave Revolts and Abolitionism, the historian of Portuguese abolition, João Pedro Marques, argues against what he describes as two misinterpretations. For Marques, these were: "first, that revolts were always ways of fighting slavery; and secondly, that the decision to end the system of slavery in most Western nations was for the most part the outcome of such revolts."(p. 5) Marques disagrees with both of these views and maintains that it is not possible to establish a correlation between slave uprisings and the acts of emancipation in the West.