The encyclopedia was purchased by Grolier in 1945. By the 1960s, sales of the "Americana" and its sister publications under Grolier—"The Book of Knowledge", the "Book of Popular Science," and "Lands and Peoples"—were strong enough to support the company's occupancy of a large building (variously named the Americana Building and the Grolier Building) in Midtown Manhattan, at 575 Lexington Avenue. Sales during this period were accomplished primarily through mail-order and door-to-door operations. Telemarketing and third-party distribution through their Lexicon division added to sales volumes in the 1970s. By the late 1970s, Grolier had moved its operations to Danbury, Connecticut.