For about fifteen years in Philadelphia, Alexander wrote primarily fiction, non-fiction, and translations for adults. Desperate for a job, he worked as a potter's apprentice for his sister. At the end of 1948, he started writing advertising copy, and he began to receive more royalties for his translations, leading him to purchase a house for his family in Kellytown. However, he lost his job after three months, requiring his wife to take up employment in a textile mill to make ends meet. Alexander continued to write diligently, though no publishers bought his novels for seven years. One of his short stories, "The Fantastic Symphony" (1949), published in the
New Directions Annual, was a surrealistic piece inspired by Berlioz's notes on the
Symphonie fantastique. Alexander's breakthrough came with his novel
And Let the Credit Go (1955), his first autobiographical work, in which he focused on his experience as a bank messenger in his adolescence. He wrote his second novel,
My Five Tigers (1956), about his cats, continuing the trend of writing about subjects familiar to him. He found work as a copyeditor and a cartoonist where he finished his last four adult publications. He wrote two semi-autobiographical novels:
Janine is French (1959) and
My Love Affair with Music (1960). Alexander co-authored
Park Avenue Vet (1960) with
Louis Camuti, who specialized in treating cats. The
American Society for the Prevention of Cruelty to Animals subsequently commissioned their history, which Alexander wrote as
Fifty Years in the Doghouse (1964). During that time he wrote two non-fiction books for children, biographies for
August Bondi and
Aaron Lopez commissioned by the Jewish Publication Society, the former of which won the National Jewish Book Award in 1959. Alexander's subsequent novel was his first of the fantasy genre:
Time Cat (1963). He later called it "the most creative and liberating experience of my life". The novel imagines a cat who can visit its other lives in different time periods, which Alexander researched extensively.
Fifty Years in the Doghouse (1964; reprinted as
Send for Ryan) told stories of how William Michael Ryan saved animals as part of his job as a special agent for the ASPCA. Almost forty years old, he then specialized in children's fantasy, the genre of his best-known works. His wartime tenure in Wales introduced him to castles and scenery that would inspire settings for many of his books. He once described it as being educational for him and "rather like being a visiting uncle, who has a marvelous time with his nephews and nieces, then goes off leaving the parents to cope with attacks of whooping cough, mending socks and blackmailing the kids to straighten up the mess in their rooms." Alexander wrote
The Wizard in the Tree while suffering from depression and published it in 1975. The character Arbican was based on Alexander and his personal struggles. In 1977 he published
The Town Cats, which received a more favorable critical reception than
The Wizard in the Tree. His next book,
The First Two Lives of Lukas-Kasha, set in a fantasy world based on 15th century Persia, was published in 1978. It won the Silver Slate Pencil Award in Holland and the Austrian Book Award in Austria. Alexander's other fiction series are
Westmark (1981 to 1984) and
Vesper Holly (1987 to 1990 and 2005).
Westmark features a former printer's apprentice involved in the rebellion and civil war in a fictional European kingdom around 1800. Vesper Holly is a wealthy and brilliant Philadelphia
orphan who has adventures in various fictional countries during the 1870s. There was some controversy about
The Fortune-Tellers (1992), a picture book illustrated by
Trina Schart Hyman. Some felt that the story was European in origin and therefore inappropriate for its African setting. Alexander's last novel,
The Golden Dream of Carlo Chuchio, was published in August 2007. Alexander helped create the children's literary magazine
Cricket and served on its editorial board. He served on the library committee of
World Book Encyclopedia in 1974 and in the board of directors in the Friends of the International Board on Books for Young People in 1982. Alexander maintained a rigorous working schedule, awakening at 4 a.m. and working until the late afternoon, afterwards enjoying his sole meal with his wife. He adhered to this routine even when he did not feel inspired, stating that he could not rely on inspiration alone. He corresponded with fans, who on occasion visited him in his home. Alexander died on May 17, 2007, of cancer, a few weeks after the death of his wife of sixty-one years. ==Themes and style==