The Grand Hotel in Point Clear, Alabama.

You said you like history. Lots of history in Baldwin County.
Excellent hotel known for its service. Great food in the area.

Short drive to Florida beaches in Navarre that has beautiful waters but less crowded than Destin.

Of course, your $500 hotel spend won’t get you many nights anywhere that I can think of, but you could stay a night at The Grand, the drive over to Pensacola and stay a night downtown (great food and nightlife) then drive east to 30A and stay a night at The Pearl.