An apple pie is a popular fruit pie, in which the principal filling ingredient is apple.
What makes the apple pie so popular is its pastry, which is generously used top-and-bottom, making it a double-crust pie (except for the deep-dish apple pie, that has a top crust only). On occasion, an apple pie is served with whipped cream or ice cream on top.
Apple pie was brought to the colonies by the British during the 17th and 18th centuries.
Nowadays, American recipes for apple pie usually indicate there is an apple filling spiced with cinnamon, nutmeg, and preferably lemon juice.