Those in leadership positions are often called upon to work more and harder to lead. I do not know your specifics but I can say there are very very many that have no job and did not get promoted.
In an at will state like Illinois you have the absolute freedom to take your talents to another company and your current place has absolutely no say about that. So the "at will" tag goes both ways and gives you a powerful freedom
If you are performing the same job tasks now as a salaried employee that you were as an hourly employee then it may not be the case that you are truly exempt from the overtime provisions of the Fair Labor Standards Act and your state's wage law. You would need to speak with an employment lawyer in your area about your situation to see if you should be receiving overtime compensation.
At a minimum I would encourage you to keep a log at home of the hours you work each day, including start and stop times, along with whatever time you took lunch. Also keep copies of your pay stubs. If it turns out you should receive overtime then you will need those records to prove the hours of unpaid wages.
From the additional information you provided to Adam, it seems to me that you are an "included employee" for FSLA purposes and that you should be entitled to time and one-half for hours worked in excess of 40 hours per week (or perhaps, in your case, 80 hours in an extended work period of two weeks, based on how you are paid)..
Even in an "at will" state, an employee cannot be fired in retaliation for making an FSLA complaint. Consult with a labor and employment lawyer who can explain your rights and adise you on the appropriate steps to take.
This question was asked a few days ago. A salaried employee can be required to work more than 40 hours per week. If you are concerned, you should speak with an employment attorney. If you remain concerned, perhaps it's time to ask for a raise and if you remain concerned, to look for a new job.
First of all, to be exempt from overtime, you must be paid at least $455 per week. If you are paid $400 a week you are simply not an exempt employee and your employer is in violation of federal and possibly state law, depending on the number of hours you work divided by your weekly pay. If your hourly pay falls below the state or federal minimum wage rate, your employer has committed additional violations. Please consider speaking with a qualified FLSA attorney. Many of us provide case evaluation at no cost.
Unless they pay you the minimum annual salary, they are obliged to pay you minimum wage and overtime. One thing you should do is to keep track of your hours. When you get put on salary, it is easy to lose track of your hours, because you don't punch a time clock any more. But, if there are issues about compliance with wage and hour laws because you make close to the minimum annual salary (or, in your case, below it), you will want to have accurate, contemporaneous records of the hours you actually worked. Keep a separate diary on which you note the hours actually worked each day.
This response creates no attorney client relationship; consult a local lawyer for help if you proceed.