Recently, while watching a documentary on YouTube, I learned about a history that made my heart race and sent chills down my spine!

Have you ever heard of 'Sundown Towns'? Literally translated, it means 'towns where the sun sets,' which sounds like a pretty name, but looking deeper, it's truly chilling.

What this means is that in the past, there were towns in America where "non-white people (especially Black individuals) had to leave the city before sunset"—a terrifying law and practice.

From the Civil War in the 1800s until 1968, there were thousands of such towns across the United States.

In fact, they even had large warning signs at the town entrances saying things like, "Black people, do not stay in our town after dark."

If you remained in the town after sunset, you could be arrested by the police or assaulted, and in severe cases, even lose your life. Isn't that terrifying?

It was said that not only was finding a home impossible, but even walking down the street at night was not allowed.

What's even more surprising? I initially thought this only happened in rural southern towns.

But it turns out there were many Sundown Towns in the Midwest, like Ohio and Illinois, and even in predominantly white towns in the East, like the New Jersey where I live!

It's hard to believe that towns that appear peaceful and clean on the surface were places where people of color had to risk their lives just to pass through...

So, in the past, Black travelers had to carry a survival guidebook called the 'Green Book' to know where they could safely sleep and which gas stations were safe.

I remember watching the movie and being deeply moved, but I had no idea that such a painful history was hidden behind the film's backdrop.

In 1968, the law changed, and officially, these Sundown Towns disappeared.

However, even today, if you visit some rural areas or certain neighborhoods in America, you can still feel the cold stares of people watching outsiders or people of color with suspicion.

As a 40-something immigrant mother living in America, I feel a heavy heart realizing that the safety we enjoy today in Palisades Park wasn't just given to us.

Knowing this hidden history behind America's glamorous facade makes me see the map of the United States a little differently.

As I drive along highways and freeways, I sometimes wonder about the cities I pass that I would have just fueled up and driven through before.

What were these cities like 50 or 100 years ago?

For some, they may have been ordinary and comfortable hometowns, but for others, weren't they places they had to leave before sunset?

Living in America, you hear the phrase 'land of the free' quite often.

But looking deeper into America, understanding who was denied that freedom is also a way to comprehend the nation better.