Library Power seeks to activate an underutilized resource--a school's library program--in ways that promote schoolwide changes in the curriculum and instruction. This three-year initiative of the DeWitt Wallace-Readers' Digest Fund, located in 19 sites across the country, connects elementary and middle school libraries more directly to classroom learning. Library Power in Philadelphia, a joint effort of the Philadelphia Education Fund and the School District of Philadelphia, began with a cohort of 11 schools midway through the 1994-95 academic year and added a second cohort of 19 schools the following year. This report adds a seventh case study site to an earlier report of six of these schools (1996) and documents the program impact through the summer 1997. All of the seven subject schools had implemented at least some of the key components of the Library Power initiative. Three of the schools achieved most of the program's objectives, another two made important strides in that direction, and two were classified as relatively low in their level of implementation. Overall accomplishments, factors explaining variations in program implementation, policy issues, and the future of Library Power are all discussed. (AEF)