This study examined independent reading behaviors and contextual factors that contributed to growth in vocabulary and literacy of fourth grade English-only (EO), limited English proficient (LEP), and fluent English proficient (FEP) children. Participants were given pre-post measures of receptive and expressive vocabulary, word reading, decoding, passage comprehension, print exposure, and attitudes toward reading. A reading management program was used to measure the quality and volume of children's book reading. Patterns of vocabulary and literacy growth were similar for EO and FEP children. More restricted access to books at home and in the school and classroom libraries related to differences in independent reading behavior between EO, FEP, and LEP children. The number of books read was found to be an inadequate measure of reading volume. However, quality of independent reading predicted posttest scores on all measures. The findings of this study suggest that it is important to use EO, LEP, and FEP categories when examining children's reading achievement, as such analyses may help researchers and policy makers to better understand factors that lead to the successful reclassification of LEP children to fluent English status. [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.]