In the US, Spring Break for elementary through high school students tends to be the week before or the week after Easter. For college students it's pretty up in the air, varying school by school, and generally doesn't coincide with Easter.
Mexico, on the other hand, is a very Catholic country. Forget calling it "Spring Break." Here, your Spring vacation days as a student (or a professional / employee) are always part of Holy Week. As an UNAM student, we got all of Holy Week off, including Palm/Passion Sunday (if we count the weekend before), Maundy / Holy Thursday, Good / Holy Friday, Holy Saturday and Easter / Resurrection Sunday. It does not, however, include Easter Monday (Monday following Easter / Resurrection Sunday). Elementary through high schools generally have two weeks of vacation, including Holy Week and the following week. For the working world, it depends on the job / company, but most people generally have off Thursday (Maundy / Holy Thursday) through Sunday (Easter / Resurrection Sunday).
This also means that basically anyone in the country that wants to take advantage of vacation days to travel will be traveling AT THE SAME TIME. And let me tell you, that's a lot of people. The trend seems to be that, whether they can afford it or not, people want to make the most of Holy week to travel.
My first year in Mexico I made a quick trip home over Easter and last year I spent the week in Maltrata, Veracruz, so I guess I never realized just how crazy (read: people everywhere you might want to be besides your house) this week gets.
This year Edson and I decided to take a trip. However, as previously mentioned, that's what pretty much everyone else wanted to do as well. We had to discard various plans along the way. One plan, for example, was trip through various parts of the state of Veracruz that I haven't seen yet: the archeological site El Tajín, the town Papántla (where the Voladores de Papántla are from), the beach in Tecolutla, and hitting a few spots I'd missed in the city of Veracruz. However, all 15 - 20 hotels we called in Tecolutla were completely booked. Have you ever heard of Tecolutla? Neither had I.
In the end, we decided to to visit places close to the DF (and then if worst came to worst we could always drive back!). We spent Thursday at the International Horse Fair in Texcoco, State of Mexico. Friday we went to the Africam Safari in Puebla, followed by a baseball game in Puebla. We had thought about going to the town Zacatlán de las Manzanas and the nearby hot springs on Saturday, but after battling the crowds for two days (and dreading the crowds that awaited us), we came back to the DF and went to the movies.
**Yes, Easter was March 31st. I'm sticking with my "better late than never" strategy.