Collier’s Encyclopedia, general encyclopaedia first published in 1950–51 in the United States. Originally in 20 volumes, Collier’s was expanded to 24 volumes for a major revision in 1962. It remained at that length until 1997, when it was printed for the last time. Microsoft Corporation acquired the copyright to Collier’s in 1998 and added the content to its Encarta encyclopaedia.
During its existence, Collier’s was a well-reputed work with coverage reflecting secondary-school and college curricula. Most of the articles were signed, many by world-renowned scholars. Collier’s was strongest in its treatment of the arts and humanities, social sciences, and botany. Major biographies received lengthy treatment; geography articles were attractively presented and received a high percentage of the print set’s space. Volume 24 contained bibliographies arranged under broad subject headings with various subdivisions; a study guide, which listed the articles in the encyclopaedia that the editors considered fundamental to a thorough understanding of a given subject; and an exhaustive, consolidated index to text, illustrations, maps, and bibliographies.