Cardio and Legs

Today I did cardio for approx 1hr followed by a 1hr leg workout. I realized the mistake I made doing cardio for so long prior to working out legs. Next time I will decrease cardio workout time by about 30 minutes prior to leg workout in hopes of seeing the workout the entire way through.

My leg workout consisted of the following:
Leg press ( 3 plates on each side) 10 reps x 3 sets
Seated machine quadriceps ( 90lbs) 10 reps x 3 sets
machine hamstring  )90lbs) 10 reps x 3 sets
standing calf raises ( using own body weight) 20 reps x 4 sets

I attempted to finish off with barbell squats which is my enemy workout. I know it is the best leg workout and it must be done but 2hrs into my gym time I was completely drained. I will attempt to do this workout the next time I walk in completely fresh.