So, Billy Graham was a really famous preacher who talked about God to a lot of people. He traveled all around the world to tell people that God loved them and wanted them to be good people. He did this for a really long time, starting way back in the 1940s!
Lots of people came to see him talk because they wanted to learn about God and how to be closer to Him. He was really, really good at talking to people and making them feel like they could trust him. He talked about things like love and forgiveness, which are really important parts of Christianity (a religion that lots of people believe in).
People still remember Billy Graham today because he helped spread the message of God to millions of people. Lots of people think that he was one of the most important preachers of the 20th century, which means he was a really, really big deal.