From what I have learned in my studies of Egypt, the people who built the oldest of the pyramids were not initially slaves. The slaves came much later during the dynastic periods of Egypt, when there had been race-mixing and a fundamental change in the cosmology/cosmogony of the original Nubian people of the continent. Slavery came about through this perversion of the cosmology, and was practiced as a result by all manner of people during that time. What we have today is a continuation of the same in capitalism, or any form of republic or so-called democracy. I'd say that today, slavery has changed in it's form, but is more prevalent than ever. People actually think they are living in freedom, and this couldn't be further from the truth. Because of this, freedom does not live as it once did with your people, long, long before Moses became a figure of Judaic his-story. The bible must be taken into context with respect to all other esoteric and prolific texts of that time in order to better grasp the story as it was originally told by your people. The Coptic bible is an interesting piece of work, for instance, in comparison to any modern christian translation.