Cate Lineberry is a bestselling author and former editor for National Geographic and Smithsonian magazines. Her latest book is Be Free or Die: The Amazing Story of Robert Smalls' Escape from Slavery to Union Hero.

Mario Livio is an astrophysicist and author of the May 2020 book, Galileo: and the Science Deniers. For 24 years he was an astrophysicist at the Space Telescope Science Institute, which operates the Hubble Space Telescope.

Jeffrey A. Lockwood is a professor of natural sciences and humanities at the University of Wyoming and the author of Six-Legged Soldiers: Using Insects as Weapons of War and The Infested Mind: Why Humans Fear, Loathe, and Love Insects.

Margaret MacMillan is a former Warden of St Antony’s College, Oxford University and a professor of History at the University of Toronto. She is the author of several books on international history including Paris 1919: Six Months that Changed the World; Nixon and Mao: the Week that Changed the World; and The War that Ended Peace: the Road to 1914.

Mitchell T. Maki is president and CEO of the Go For Broke National Education Center in Los Angeles. Founded in 1989, the organization works to preserve and honor the unique legacy of Japanese American World War II veterans.

Barbara Maranzani is a New York–based writer and producer covering history, politics, pop culture, and more. She is a frequent contributor to The History Channel, Biography, A&E and other publications.

J.S. Marcus is a freelance journalist based in Berlin. His work appears in The Wall Street Journal, The New York Times, and other publications.

Lisa McCubbin is the author of BETTY FORD: First Lady, Women’s Advocate, Survivor, Trailblazer and three New York Times bestsellers with Secret Service Agent Clint Hill. Follow her on Twitter @Lisa_McCubbin.

Una McIlvenna is a literary and cultural historian specializing in early modern and 19th-century Europe. Her most recent book, Singing the News of Death, explores the phenomenon of execution ballads. She is also the author of Scandal and Reputation at the Court of Catherine de Medici. Una is an Australian Research Council Future Fellow and Senior Lecturer at the Australian National University, and can be reached at unamcilvenna.com.

Pat McManamon's sportswriting career has spanned more than 35 years and included stops at ESPN and the Akron Beacon-Journal. He shares a love of history with his older brother, a Renaissance historian and nautical archaeologist.