Data from two different sites were used to examine how exposure to a highly academic curriculum is related to growth in beginning literacy and early reading skills from kindergarten through the end of third grade. In one site students in one school used the Direct Instruction (DI) program, "Reading Mastery (RM)", from kindergarten through grade 3, while students in a nearby school with similar demographic characteristics and entry skills had "Open Court". In the other site, comparisons were made between one cohort that had a whole language kindergarten experience and began the "RM" program in first grade with two other cohorts who had "RM" throughout their K-3 career. In both sites, students exposed to RM had significantly greater growth in Nonsense Word Fluency scores from mid-kindergarten through the end of first grade. In addition, in both sites Oral Reading Fluency scores at the middle of first grade exhibited strong differences in favor of the "RM" students. For students in the Pacific Northwest site these differences persisted with very little change through the end of third grade. However, for those in the Midwestern site, where all cohorts had "RM" in grades 1-3, the differences gradually declined, although differences remained in favor of the "RM" group at the end of third grade. (Contains 5 tables and 4 figures.)