by the early 1970s, ace books became a major division of the old publisher, charter communications. it was in the hippodrome building, 1120 avenue of the americas, in new york city. in 1972, grosset &amp; dunlap bought ace, and in 1982, grosset &amp; dunlap was bought by g.p. putnam's sons. ace was likely the only profitable part of grosset &amp; dunlap by this time. ace soon became the science fiction imprint of its parent company.