The Hardy Boys evolved again, beginning in 1959. Many readers had complained about racial stereotypes in the older volumes, and under pressure from the publishing company, Harriet Adams agreed to a massive re-writing project to update the series. Svenson oversaw the project, eventually re-writing some of his own early books. The new books were shorter, free of negative racial stereotypes, and included more action and exotic locations. Svenson continued his mission to engage children with exciting stories, while simultaneously teaching them. He intentionally used vocabulary that was above the reading level of his target audience, in order to encourage them to look words up in the dictionary. He also traveled to the exotic locations he described in his books, in order to authentically portray cultures outside of the United States. He continued to write Hardy Boys books until his death in 1975. One of his last changes to the series was a change on the back cover of the books. On the advice of his granddaughter Jennifer, he changed the wording on the back cover of the Hardy Boys from “All boys…” to “Anyone." Some critics have complained about the changes to the series; others have lauded his removal of sexist and racist language, and his willingness to keep the books updated and modern.