The results of the first attempt at a comprehensive survey to identify and document interlibrary cooperation activities in each of the 50 states and United States territories are reported. Compiled by the Interlibrary Cooperation Subcommittee of the Association of State Library Agencies, the report is arranged by state and territory. It contains information on state level organizations responsible for interlibrary cooperation activities as well as on single- and multi-type library systems, networks, and consortia. Also included is information on: (1) funding patterns by state and territorial library agencies for interlibrary cooperation functions; (2) communication devices and network hardware; (3) machine readable data bases; (4) interlibrary services to special user groups; and (5) legal bases and barriers for multi-type library cooperation. A matrix giving the number of U.S. libraries by type appears in the appendixes. (Author/PF)