In 1998, he published a biography of Alexander Graham Bell. It was on the market briefly before Robert V. Bruce published a damning indictment, detailing sustained plagiarism of his own work, "Alexander Graham Bell and the Conquest of Solitude". Far from being a little-known work, the latter had in fact been nominated for the Pulitzer Prize in 1973. The indictment, published in the American Historical Association's house journal, counted instances of plagiarism on 80 percent of the pages published. Mackay paid his publishers to withdraw the book from circulation, and Bruce agreed not to sue.