Why is this Passover different from most others? The first day coincides with Tax Day for Americans. Jews remember the bitter hardship and forced labor of slavery in Egypt. Scholars, however, can find no evidence of modern era-style slavery (or of Jews residing in or escaping from in Egypt). As for the pyramids there are records of payments to laborers, typically farmers who had nothing else to do at certain times of year. A “slave” in ancient Egypt may simply have been a person subject to a 20% tax that free Egyptians did not pay.
[To the children at last night's Seder I pointed out that "the plagues visited upon the Egyptians were so bad that their civilization lasted only about 2000 more years."]