Inquiry is the process by which teachers give students an open-ended question, and then students investigate the evidence and draw conclusions based upon their findings. This method promotes critical thinking, as students cite evidence to support their opinions. Inquiry is most effective when it builds upon students' prior knowledge. To promote historical inquiry skills among their students, the authors made their sixth-grade students compare various civilizations from the 1500s as part of their school project. Their students were made to study cultural groups that have studied to some extent in their previous grades. They were made to study the Inca, the Aztec and Maya, several Native North American Tribes, and a few European societies in more depth. The goal of the project was to decide which of the groups appeared to the most "civilized" based on their investigation. (Contains 11 notes.)