With his widely read novel “Invisible Man,” Ralph Ellison ignited a conversation and an awareness of racial alienation in America that had the potential to help bridge the gap between the nation’s races.

But as we celebrate what would have been his 100th birthday on Saturday, it is almost staggering to see how little has changed since Ellison published the book in 1952.

Black people — and black men in particular — are still viewed and judged as though we were all one person, with one mind, and that we either are criminals or are about to become criminals.

We are still treated as if we are less than everyone else, no matter the degrees we may possess, how impressive our job titles or our contributions to society.

Indeed, as we celebrate Ellison today, it is a shame to have to say that the black man as an individual is still “invisible” and that the country has a long way to go.

I was painfully and frustratingly reminded of this just last week in Brooklyn.

It was the middle of a snowstorm, mild by New York standards, and a bunch of friends were gathering for a game night in. Since my friend’s house was only a few blocks away, and the snow and wind were really more of an annoyance than anything else, I didn’t see any reason not to go. I grabbed a backpack, put on a hoodie to block the snow from my face and put on a coat over it to keep me warm.

On the way, I stopped by a Duane Reade pharmacy in my neighborhood to pick up supplies. When I walked into the store I made several observations. The first was that the store was empty, with the exception of one other customer who I believe was Native American (I apologize if I got that wrong). It was near closing time. And the entire staff on duty — from security to manager — was black.

I didn’t think much of it, and went about my business. It’s what happened next that took me off guard.

After dusting off the excess snow from my jacket and wiping my feet, I found myself comparing two similar products in the middle of the store. I was in plain sight, right in front of the cashier. All of a sudden, the manager’s voice comes across the store PA system.

“Guard, please walk the floor.”

At this moment, as the only African-American customer in the store, I am immediately made aware of my blackness, my lack of individuality and the impossibility of being seen not as a thief but as a regular customer.

To them, I’m just another black kid from the area wearing a hoodie and carrying a backpack — intent on shoplifting.

The guard does as he is asked and begins his round of the sales floor, but as he approaches me he slows down, stares and stands in place as if to indicate that he knows I am up to no good.

Calmly, I walk on to the next aisle, where the only other customer in the store is also standing. I really want to give the guard the benefit of the doubt; after all, he’s only doing what he was asked.

But as he proceeds to walk up to the aisle I am now in, stare at me again, walk off, double back around and repeat, I have to face facts. Because I’m black, it was predetermined that I would do something wrong and because of that I needed to be followed and monitored like a common criminal.

Thoroughly pissed, I grab my items and go to pay. The cashier rings me up and I say to him:

“I have to say, it feels really nice to know that having two college degrees and never breaking the law mean nothing when I come into your store. I guess because I’m black, wearing a hoodie and I have a backpack on, I must be a thief, right?”

The cashier — who is black, remember — tries to laugh it off, detecting my sarcasm.

“It’s not like that,” he says.

"I’m the only black customer in here, do you think I’m stupid?” I ask. Unresponsive, he just finishes ringing me up and starts to bag my things.

I stop him.

“No, thanks, I don’t need a bag. I’ll put it in my backpack with the rest of my contraband.”