Graduating from high school is an important step toward becoming a successful adult. It is evidence that one has met the standards set by the public school system. Standards-Based Reform has been pursued since the 1980s and culminated in the development of the Common Core State Standards that were implemented by most states between 2011 and 2015. The Common Core State Standards are focused on post-graduation outcomes. However, it is unclear whether the implementation of the Common Core has had any impact on graduation itself. The purpose of this study was to examine trends in the graduation rate in the United States to determine the effects, if any, of the implementation of the Common Core State Standards on the secondary school population as a whole and on several subgroups. Using the four-year adjusted cohort graduation rates (ACGR) the researcher calculated gain scores by finding the difference in the average graduation rate for three years prior to implementation and the average graduation rate for three years following the implementation of Common Core State Standards for all states that implemented the standards and for the same years for states that did not implement the Common Core State Standards and compared the entire population as well as several groups based on ethnicity and educational barriers. While the difference in gain scores between states that implemented the Standards and states that did not was not found to be significant for any year of implementation, it was noted that almost all states in both the treatment and control groups had positive gain scores indicating higher graduation rates after the Common Core State Standards Initiative. When looking at differences between groups, the study found evidence that the gap between graduation rates for ethnic groups with the lowest graduation rates and the highest graduation rates is narrowing but still too large. There is much work to be done to ensure that all students graduate with the knowledge and skills they need to succeed. [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.]