What should I ask Ken Burns?

I will be doing a Conversation with him, here is the beginning of his rather formidable Wikipedia entry:

Kenneth Lauren Burns (born July 29, 1953) is an American filmmaker known for his documentary films and television series, many of which chronicle American history and culture. His work is often produced in association with WETA-TV and/or the National Endowment for the Humanities and distributed by PBS.

His widely known documentary series include The Civil War (1990), Baseball (1994), Jazz (2001), The War (2007), The National Parks: America’s Best Idea (2009), Prohibition (2011), The Roosevelts (2014), The Vietnam War (2017), and Country Music (2019). He was also executive producer of both The West (1996), and Cancer: The Emperor of All Maladies (2015). Burns’s documentaries have earned two Academy Award nominations (for 1981’s Brooklyn Bridge and 1985’s The Statue of Liberty) and have won several Emmy Awards, among other honors.

His forthcoming book is the lovely Our America: A Photographic History.  So what should I ask?