Is it possible to track your iPhone that was stolen?

Yes. It has been possible since the 1G era (analog).

Having worked previously for one of the largest cell providers of the time, I tracked stolen phones quite successfully. Typically, stolen phones will be used by the thief immediately. Contact your carrier (usually best face to face in one of the branches) and ask for the last several numbers called. This is a round about way to do it, and works well when the thief is a child (common). Have the phone turned off, and purchase a cheap burner phone and have it activated with your number.

Now, begin calling the last numbers called, ostensibly by the thief, and any incoming calls. Begin by letting them know that you now know who they are and that you will be turning all this information over to the local police when you file the theft complaint of your $500 (felony theft) cell phone, and that by not divulging who called them, they are accessory to the crime (this is not a lie and you are not a lawyer--are you?). Let the person know that if he cooperates in helping you recover the phone, that it will all go away.

If this is not successful, have the cell phone provider "ping" the phone. They can tell you what tower it is bouncing off, and might be able to triangulate the location of the phone. If the GPS is enabled, they may be able to get you cooredinates within ten feet of its actual location.