95 Honda Civic Hesitation/shaking when accelerating

SYMPTOMS: car hesitating, shaking and misfiring on acceleration in
every gear, smoothing out at higher RPM. the behavior worsened as the
engine heated up.

CAUSE: faulty (old and worn) spark plugs that were well past their
expiration.

SOLUTION: replace them with new ones.

NOTES: well, it was the spark plugs. I don't feel bad about replacing
the fuel filter, distributor cap and rotor as well though, and I still
might replace the wires because these are all parts that needed
replacing anyway. Plus, the problem with my car not starting after a
heavy rain was not likely caused by bad spark plugs. I have yet so see
if that still occurs. I did the water spray test though and I didn't
notice a change. I also might need to set my idle speed. My car seems
to be idling at lower RPM than it did before I changed the distributor
cap and rotor. I would like to check the timing and do anything else
that might increase my gas mileage.

Thank you all so much for your help. I can't tell you how much I
appreciate it.