This study demonstrates the impact of an Early Reading First intervention on preschool children's language and literacy development using an ex post facto, causal-comparative research design. The project's professional development model was evaluated to produce a process and outcome evaluation to answer two overarching research questions: (1) What was the professional development model implemented during the 2010-2011 academic year? (2) Did enrollment in Early Reading First classrooms improve children's language and literacy development with statistical significance when compared to demographically similar children not enrolled in ERF classrooms? In 2011, 67% of the nation's fourth grade students failed to achieve reading proficiency (NAEP, 2011). Research demonstrates there is a direct and negative relationship between this marker and ever-widening achievement gaps, high school dropout rates, unemployment, and the continuation of poverty, especially for children impacted by the effects of poverty. Longitudinal studies, however, provide strong evidence of long-term positive effects of children's enrollment in high quality early childhood programs that mitigate the effects of poverty. The Early Reading First intervention provided professional support to educators working in 14 preschool classrooms in 5 urban programs. Literacy coaches supported teachers' implementation of content learned in two literacy interventions. A Response to Intervention (RtI) model informed the use of child-level data. Secondary analysis was conducted on child-level data from an Early Reading First (ERF 2009) and an Early Childhood Educator Professional Development (ECEPD 2006) database. In total, 441 children were assessed using measures of the "Peabody Picture Vocabulary Test" (PPVT-IV) and subtasks of the "Phonological Awareness Literacy Screening" (PALS-PreK) with 207 enrolled in ERF classrooms (treatment condition) and 234 enrolled in control classrooms. A multivariate analysis of covariance (MANCOVA) revealed that children enrolled in Early Reading First classrooms demonstrated statistically significant outcomes in receptive vocabulary, letter knowledge, name writing, and letter sound recognition when compared to demographically similar children. This study serves to inform similar interventions by retrospectively mapping a logic model of the professional development intervention. It also serves as the institutional memory of one organization's efforts to support an infrastructure of early education and care by creating space for community dialogue about best practices in early childhood education, increasing the rigor and definition of professional development, and building a common understanding in the use of data to inform its work with children, families, and educators. [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.]