Easter and Passover

So, I've been pondering the relation between our current Easter and the Jewish Passover. I know that traditionally we have been taught that Christ's atonement occurred during the same time as the Passover Feast. I'm not discrediting that, I'm just wondering why Easter came so early this year and how the Passover doesn't happen until April 19th. Although they are both "movable" holidays, I assumed that those dates would be set corresponding to each other. Obviously they are not. So, if anyone knows how this happened (except that Passover is a non-Christian holiday and Easter is actually a changed Pagan holiday...I get that part). All I can discover is originally Easter was held in correspondence with the Jewish Passover. Then came a difference of opinion/belief which led to a debate of holding Easter on Nisan 14 or the Sunday following that date. Eventually they chose to follow a lunisolar calendar to determine the date in order that they might separate themselves from Judaism (much the way that the founders of the USA wanted to differentiate themselves from mother England). Ironic that the Jewish holiday marks the death and resurrection of the Lord, yet Jews reject Christ, however, early Christians didn't want to be associated with that culture and chose to change the date of celebration. Not that this is a doctrinal point, but it does demonstrate the influence of Man's decisions in the observance of Christian beliefs and the freedom of the leaders of early apostate Christianity in defining things.