A large magnetosphere magnetic field database compiled from the measurements of 11 Earth-orbiting spacecraft during 1966-1986 is described. The 11 contributing spacecraft (Explorer 33 and 35, IMP 4, 5, 6, 7 and 8, Heos 1 and 2, and ISEE 1 and 2) provide data between 4R(E) and 60R(E), Which have been edited in order to exclude data outside the magnetosphere. Currently, the database totals more than 79,000 records, which sum to a total of more than 1600 spacecraft days in the magnetosphere. Each of these records contains the average total field vector in geocentric solar magnetospheric coordinates, disturbance field vector (measured field minus Earth's internal field), time information, spacecraft position, AE, AL, Kp. and Dst geomagnetic indices, and associated solar wind and interplanetary magnetic field parameters when available. These data have constituted and will undoubtedly continue to constitute the standard database for magnetospheric modeling studies. They are also appropriate for statistical studies of the magnetic field and its dependence on solar wind quantities. Plans are to update this database in the future with data from additional spacecraft.