He has written three books, The Meat Racket: The Secret Takeover of America's Food Business,[1] the New York Times best-selling Kochland: The Secret History of Koch Industries and Corporate Power in America,[2] and The Lords of Easy Money: How the Federal Reserve Broke the American Economy.

His work has appeared in The New York Times, The Wall Street Journal, Fortune, and Bloomberg Businessweek.

In 2014 Leonard joined the New America Foundation[4] where he finished his first book, The Meat Racket which received positive reviews,[6] and has been praised as tracing "the evolution of the modern American meat industry".

[7] While at New America he began work on his second book, Kochland,[4] which was published in 2019 to positive reviews.

[10] In 2019, Kochland was also a finalist for the Financial Times and McKinsey Business Book of the Year Award.