LeBron James says the racist vandalism at his Brentwood home proves one thing -- no matter how much money or fame he has, "Being black in America is tough."

TMZ Sports broke the story ... someone spray painted the n-word across the front gate of Bron's $20 million estate. Cops are hunting for the perpetrator.

LeBron spoke about the incident Wednesday afternoon at a media event for the NBA Finals -- saying his family is safe ... and that's the most important thing.

He also said the incident proves that "racism will always be a part of the world and a part of America."

LeBron also referenced Emmett Till -- the 14-year-old black kid who was brutally beaten to death by racist white people after they accused him of whistling at a white woman.

"I think back to Emmett Till’s mom actually. It’s one of the first things I thought of. The reason she had an open casket was because she wanted to show the world what her son went through as far as a hate crime and being black in America."

"No matter how much money you have, no matter how famous you are, no matter how many people admire you, being black in America is tough and we got a long way to go for us as a society and for us as African Americans until we feel equal in America."