In all my years, Spring Break has always been in March, including when I was in college - so that's almost 30 years. It does often coincide with Easter, but that's due to Easter moving (and not Spring Break). Here's the Easter dates for the next 40+ years:
http://users.sa.chariot.net.au/~gmarts/eastcalc.htm
Also, note that it varies depending upon whether you're Orthodox or Western. Also, there are Jewish and Muslim holidays that tend to roam as well.
My kids go to a private Catholic school, so they also get the entire Easter holiday off - it starts with Easter Thurday and ends with Easter Monday. Personally, we enjoy the options we have of traveling either in March for Spring Break and/or choosing to see family for Easter. Personally, I don't consider visiting family to be a vacation ;) For me personally, the March spring break is perfect, since I almost always have a meeting before or after, so my kids travel with me either to or from the meeting.
It's interesting as you likely won't ever get two people to agree on what's convenient, since all our families have unique perspectives, due to ages of kids, different school and work schedules. We had an incredibly long discussion about my work meetings, which occur 3x per year as to how it impacts folks' personal lives. For example, folks in Europe don't like the timing for our summer meeting because it often coincides with their long summer vacations. For University folks, if the meeting isn't during their Spring Break, it's very difficult to attend.
So, this is definitely YMMV, but personally not something I would over stress on. FYI, most school schedules have Spring Break defined 9 mos before. And, Easter is determined for decades. So, planning earlier is always a good idea. Most airlines will give you a credit if the airfares go down.