Front Derailleur/Shift Stuck

I took the wheels out for a ride this afternoon and realized the front derailleur was stuck. Initially the chain was in the small ring, but the derailleur (D from here on out) was stuck in position for the large chain ring.  I manually adjusted the chain and went for my ride (it's relatively flat with a few rolling hills).

 When I got back I took a closer look and found that I could not manually move the D with my hand. I can move the shift lever as if I were moving to the small ring, but can't actually move it in the other direction as though I were shifting to the large ring.

I'm new to biking and haven't done anything to my bike other than change a flat. Does it sound like adjusting the limit screws would do anything? Any ideas?