Pesach: Festival of Freedom
In every generation, all are obligated to view themselves as having personally left Egypt, since it is said, "And you shall explain to your child on that day, 'It is because of what Adonai did for me when I went free from Egypt'." Therefore we are obligated to thank, praise...and bless the One who performed all these miracles for our ancestors and for us, for bringing us from slavery to freedom, anguish to joy, mourning to festival, darkness to great light, and subjugation to redemption.
--Mishnah, P'sahim. Also in the Haggadah