Why would a ford escort steering wheel shake at low speed?

If your tires are properly inflated and they are in good condition, take your car in to have the tires checked for proper alignment and balance.

Your tire could have been knocked out of alignment upon hitting the curb while parking.

After having my brakes fixed and a couple tires replaced, I experienced the same problem. It is an easy fix but you can't do it yourself. I went a long time before getting it fixed on my car but the longer you wait the more apt you are to be damaging your rims and your car doesn't respond as quickly when the tires aren't perfectly set, aligned and balanced.