Known as "crusades," Billy Graham traveled the world delivering sermons to large audiences. By some estimates, he preached to more than 210 million people in his lifetime. BILLY GRAHAM premieres Mon May 17 at 9/8c → pbs.org/wgbh/americanexperience/films/billy-graham | American Experience | PBS

Today, we honor the life and activism of Dr. Martin Luther King, Jr.. Billy Graham maintained a close friendship with Martin Luther King, whom he called "Mike." Watch this short clip to see a glimpse into their friendship and how Billy Graham advocated for racial equality. | Billy Graham Library