Maggio was the author of 24 books, including groundbreakers that insisted on inclusive language long before the subject became popular. Her titles include “How to Say It: Choice Words, Phrases, Sentences & Paragraphs,” which sold 3 million copies, and “The Nonsexist Word Finder: A Dictionary of Gender-Free Usage,” published in 1988, one of the first guides to using inclusive language. “Unspinning the Spin: The Women’s Media Center Guide to Fair and Accurate Language,” was published posthumously in October.