In 1942 an advisory board to the Library of Congress drafted a proposal for a national program of cooperation among research libraries, aimed at acquiring "at lease one copy of every book published anywhere in the world, ... which might conceivably be of interest to a research worker in America." And thus was born the Farmington Plan, which began operation in 1948 under the sponsorship of the Association of Research Libraries. In 1972 the failing plan was abandoned. This is the first in-depth study of the plans shortcomings and achievements.