This report contains data on state library agencies in the 50 states and the District of Columbia for state fiscal year (FY) 2004. The data were collected through the State Library Agencies (StLA) Survey, the product of a cooperative effort between the Chief Officers of State Library Agencies (COSLA), the U.S. National Commission on Libraries and Information Science (NCLIS), the National Center for Education Statistics (NCES), and the U.S. Census Bureau. The purpose of the StLA Survey is to provide state and federal policymakers, researchers, and other interested users with descriptive information about state library agencies. The data collected are useful to (1) chief officers of state library agencies; (2) policymakers in the executive and legislative branches of federal and state governments; (3) government and library administrators at the federal, state, and local levels; (4) the American Library Association and its members; (5) library and public policy researchers; and (6) the public, journalists, and others. Decision-makers use this survey to obtain information about services and fiscal practices. This report presents selected findings and background information about the survey. The body of this report is composed of tables providing an overview of state library agencies during the 2004 fiscal year. The tables present data on the following five main topics: (1) Governance--describes the organizational location of state library agencies within state governments; (2) Collections and Services--characterizes state library agencies in terms of holdings, library service transactions, and services to libraries and systems; (3) Service Outlets and Staff--describes the availability of state library agency locations and bookmobiles providing services to the public or specific constituencies and characterizes staff and the functions they perform; (4) Revenue--identifies various sources of state library agency revenue or income; and (5) Expenditures--describes how state library agency funds are spent. Finally, references and two appendixes supply supporting information. Appendix A provides technical information about the survey, data processing, and response rates. Appendix B contains the survey instrument, instructions, and definitions of terms used in the survey and this report. The survey asks each state library agency about the kinds of services it provides, its staffing practices, its collections, its income and expenditures, and more. The data include services and financial assistance provided to public, academic, and school libraries, and to library systems. When added to the data collected through the NCES surveys of public, academic, and school libraries, these data help complete the national picture of library service. (Contains 11 tables.)