Beginning in 2002, with the election of Mayor Michael Bloomberg, New York City's Department of Education undertook an unprecedented overhaul of the largest school district in the United States. Over the next 10 years the Department of Education closed more than 25 large, underperforming high schools, and created almost 200 new, small high schools, which, by the end of the decade, were serving approximately 30% of public high school students in the city. The first classes began graduating in 2006, and many of the "New Small Schools" graduated more students on time than many of the large schools they had replaced, in some cases even surpassing the citywide average. These increased graduation rates played a role in the increase in New York City's overall 4-year graduation rate from consistently around 50% in the late 1990s to more than 66% by 2012. This study analyzed the graduation rates and the odds of on-time graduation for all students attending the 172 New Small Schools created between 2002 and 2009 and Other High Schools. This study also examined the graduation rates and odds of on-time graduation for student-population subgroups across race and ethnicity, English-language ability, and other sociodemographic and student-ability characteristics. The study looked at the 4 incoming 9th grade cohorts from 2006 to 2009 and found that the Other High Schools had a slightly higher overall graduation rate than the 172 New Small Schools. However, when controlling for individual- and school-level factors, the odds of graduating on time for Individualized Education Program, English Language Learner, Black, and Latino students were between 10% and 12% higher at the New Small Schools than for students at the Other High Schools. The analysis raises many areas that require further research, as many factors could have influenced the results, including changes to admissions policies, the long-term sustainability of the New Small Schools' graduation rates, and the effects of small schools deflecting students with special needs to surrounding large high schools. Finally, this study informs policies on small-school creation, particularly regarding the systemic supports necessary for new small schools to establish structures at scale to achieve higher on-time graduation rates. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]