The effective teacher in the classroom is both the starting point and the engine of excellent and meaningful education. That is because excellent teachers are not only the single most important in-school factor in student learning, the best of them are the key factor in improving the instructional practices and strengthening the skills of their peers. In this report, Lowell Milken, Founder and Chairman of the National Institute for Excellence in Teaching, discusses the following topics: (1) why developing teacher leaders is important and urgent; (2) conditions required to develop and sustain teacher leaders; and (3) what needs to be done to extend the reach of systemic reform to more districts and schools.