From a historical perspective, why were the Jews in Egypt? On what basis were they considered slaves instead of sovereign citizens of a foreign nation? I have basically no prior knowledge of this geographical region or era, historically or biblically.
From a historical perspective, there is no evidence there were any Jews in Egypt ever, and certainly not as slaves. The "slaves building pyramids" is a myth, that is contradicted by all available evidence.
Starting in the 70s, the University of Tel Aviv under the direction of Israel Finkelstein funded a huge amount of archaeological digs in Egypt to prove the historicity of the story of Exodus. He co-authored a book entitled The Bible Unearthed: Archaeology's New Vision of Ancient Israel and the Origin of Its Sacred Texts about his findings. In it, he mentions not only could they find no proof of the Exodus story, but also no proof that Jews ever lived anywhere in Egypt.