Who was Mario Pei?

From Wikipedia: Mario Pei

[...] Pei was born in Rome, Italy, and emigrated to the United States with his parents in 1908. By the time he was out of high school he knew not only English and his native Italian but also Latin, Greek, and French. Over the years he became fluent in several other languages (including Spanish, Portuguese, Russian, and German) capable of speaking some 30 others, and acquainted with the structure of at least 100 of the world's languages.

In 1923, he began his career teaching languages at City College of New York, and in 1928 he published his translation of Vittorio Ermete de Fiori's Mussolini: The Man of Destiny. Pei received his doctorate from Columbia University in 1937, focusing on Sanskrit, Old Church Slavonic, and Old French.

In 1937, he joined the Department of Romance Languages at Columbia University, becoming a full professor in 1952. In 1941, he published his first language book, The Italian Language. His facility with languages was in demand in World War II, and Pei served as a language consultant with two agencies of the Department of War. In this role, he wrote language textbooks, developed language courses and wrote language guidebooks.

While working as a professor of Romance Philology at Columbia University, Pei wrote over 50 books, including the best-sellers The Story of Language (1949) and The Story of English (1952). His other books included Languages for War and Peace (1943), A Dictionary of Linguistics (written with Frank Gaynor, 1954), All About Language (1954), Invitation to Linguistics: A Basic Introduction to the Science of Language (1965), and Weasel Words: Saying What You Don't Mean (1978).

Pei penned The America We Lost: The Concerns of a Conservative (1968), a book advocating individualism and constitutional literalism. In the book, Pei denounces the income tax, as well as communism and other forms of collectivism.

Mario Pei was also an internationalist who advocated the introduction of Esperanto into school curricula across the world to supplement local languages. [...]

I remember reading some of his books from the library when I was a teen, and interested in languages. He seemed very well informed. Many of his books are still available (used), on Amazon.com. I suspect that his political views are not popular with the Brave New World crowd. See the original Wiki page for embedded links.