This week we mark Black History Month with a look at how some of the city's historically black neighborhoods have changed since NY1 launched 25 years ago. We begin in Harlem, where longtime residents have helped transform the community. But as our Michael Scotto reports, those changes are bringing big challenges to what's been considered the capital of black America.

Patricia Pates Eaton recalls how Marcus Garvey Park looked when she bought her brownstone in the early 1980s.

"Oh, it was barren, absolutely barren," she said.

At the time, many houses in Central Harlem were boarded up. Vacant lots were everywhere.

Now, blocks have been rebuilt, thanks to longtime residents like Eaton.

"Oh, the quality of life has greatly improved," Eaton said.

Over the last quarter century, 125th Street has been reborn.

Street vendors were pushed out and new stores opened up. As in the rest of the city, crime has plunged.

That in turn helped lead to an influx of new residents.

From 1990 to 2014, the population in Central Harlem grew from about 100,000 to 130,000.

But at the same time, it's become much more white and less African-American.

In 1990, blacks accounted for roughly 90 percent of the population. Now they make up less than 60 percent. Whites, meanwhile, went from one percent to roughly 12 percent.

The newcomers are wealthier, and, according to Eaton, not as social.

And people who have lived in the area for years risk being displaced.

"I'm for people who don't have a lot of money to be able being able to live here too. They should not be pushed out to the outer reaches of New York because they can't afford a $2,000 apartment," Eaton said.

It's not just rents that have soared. Average home prices increased by 270 percent from just 1996 to 2006.

That's a concern to residents who rent in buildings being converted to condos.

Gilda Gillim has lived nearly her entire life in Harlem.

"What I do not like is when people feel like they're entitled to something and I'm not," she said.

Newcomers have brought trendy restaurants. Soon, a Whole Foods will open. At the same time, historians lament the loss of buildings significant to black history.

"Over the past 10 years, there have been something like 20 houses of worship in Harlem, which have been turned into luxury housing," said Michael Henry Adams, a historian.

New business owners say they're mindful of the forces of gentrification.

Marcus Samuelsson owns the Red Rooster. He moved to Harlem in 2002, years before he opened the restaurant, to begin understanding the neighborhood.

"A community, it's very important to be sensitive to the community leaders who built it," he said.

Leaders who built a community that is in the midst of sweeping changes.