The purpose of the current research is to determine the effect of changing the English Language Art curriculum on the reading growth of fourth-grade students who attended a public school district located in a suburban community in the Northeastern part of the United States. This ex-post facto study is designed to evaluate the effectiveness of the Teachers College, Units of Study for Teaching Reading curriculum (commonly referred to as Reading Workshop). The study was conducted, with quantitative data collected, to compare the reading growth of students in the year prior to the curriculum change (N = 405) to that of students in the first year of the curriculum change (N=323). This analysis used data for all students, and further, compared reading growth by gender and by reading level. It drew on archival data, including student gender and beginning and end of fourth grade Fountas and Pinnell BAS scores from the 2017-2018 and 2018-2019 school years. Based on their Fountas and Pinnell BAS scores at the beginning of their fourth-grade year, each fourth-grade student was identified as a below, on, or above grade-level reader. The findings indicated whether or not there is significance for the main effects of curriculum, gender, and reading ability on students' reading achievement. The information gained from this study can be used to influence districts' decisions on the evaluation of the implementation of the Teachers College, Units of Study for Teaching Reading curriculum, reading intervention programs as well as teacher training and professional development. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]