I am employed full time and paid a salary. Can my boss have me work more than 40 hrs/wk without overtime pay?

I have been working for this one commercial construction company now since 1994. I have always worked a minimum of 40 hrs a week but on an average, I would work more than 45 hrs per week without being paid any overtime, and I had no qualms with that. Over the past few months though, I have been working up to 15 hrs per day 4 days a week = 60 hrs. And this work is out-of-town and away from my family. Even on my days off, I will sometimes be told to "come in" and help other employees with their projects even though they (other employees) only work a 40 hr week. I have been informed by the owner on a regular basis that "times are tough" and "we all have to make sacrifices" when he flies to the Bahama's and cruises around on his 70 ft yacht every other week and we (the employees) have rarely been given more than 1 week vacation during any given summer.....It just doesn't seem right. We employees have been a substantial part of the owner being able to have the luxuries that he has, and for him to have me work more than 20 hrs of overtime every week and not expect to compensate me for it...seems ridiculous and unfair and possibly illegal. Or, maybe this is just the way it is and I should shut-up and be thankful I have a job. What do you think?