Chapter 1: Introduction

This monograph has the luxury of investigating the evolution of the geometry curriculum in the United States over the past 150 years, a luxury that no regular-length article can afford. Other scholars who have written histories of mathematics curricula have impressed upon their readers the benefits that such endeavors can have, such as preventing mistakes made repeatedly in the past by curriculum developers, policy-makers, teachers, and educational researchers. My goal is somewhat different, and perhaps less ambitious, in that I hope to increase the mathematics education community’s awareness of the shape and nature of the geometry curriculum as it currently stands by investigating both its historical roots and the many events and influences that have led to its present state. By revisiting past decisions and debates, I aim to encourage readers to think about how things might have turned out differently— Could grade 10 geometry have been a course devoted to solid geometry? Could the algebra course have shouldered the responsibility for teaching proof?—and how things may yet change in the coming decades.