If laid off from a position does it have to be offered back to me if refilling it 3 months later as a full time position?

I held a full time salaried exempt management postilion with a nationwide company through the end of 2013 when 45 members of management were laid off. No reason was provided. My former position at the same location with the same title is being advertised as available as of today, 04/10/14. Is there any legal requirement to offer me that position before hiring from the general public or do at-will laws apply regardless of lay-off?