Man is by nature a political animal. So said Aristotle. Get them interested in politics early with these United States Capitol Building Blocks by Haba. The set includes 75 pieces in 25 shapes (including landscaping) made of wood.A gift of bicameralism, the legislative process and neoclassical architecture all in one. We think it would make a great gift for the older set as well.
About $45 here and available elsewhere.