 In the northern states, pumpkin pie was popular, as pumpkins were plentiful.Once the British had established Caribbean colonies, sugar became less expensive and more widely available, which meant that sweet pies could be readily made.Molasses was popular in American pies due to the rum and slave trade with the Caribbean Islands, although maple syrup was an important sweetener in Northern states, after Indigenous people taught settlers how to tap maple trees and boil down the sap.