An image from Freedman's Town in the Fourth Ward of Houston, courtesy of Flickr user Patrick Feller under a Creative Commons license.

In the weeks leading up to the Obama administration's announcement this month of major new rules targeting segregation, the civil-rights lawyers and housing activists I talked to often sounded exhausted. From waiting, and advocating, and waiting. From bearing the load of their own skepticism.

Some of them had been fighting to repair flaws in the Fair Housing Act from the moment it passed, in 1968. Many had worked on a campaign to pry a similar rule from Department of Housing and Urban Development more than 15 years ago, only to watch it collapse in the Clinton years.

Then they showed up again, pressing the same demands, when Barack Obama came to town. They met with one HUD secretary, then another, still waiting.

"You don’t feel old until you meet a HUD secretary who was born when you were trying to get the Fair Housing Act enforced across the United States," said Shanna Smith, the president of the National Fair Housing Alliance. She was talking about Julian Castro, 40.

This is one way to couch the significance of this moment — it has been a very, very long time coming.

What will happen next is to be determined, depending on how communities react to HUD's rule, how serious the government takes enforcement, and how much the next administration values this, too. But the new rules, combined with a major fair-housing ruling from the Supreme Court in June, constitute, as Minnesota law professor Myron Orfield put it to me, "the first real legal advance on residential segregation" in nearly 50 years.

In the last week and a half, we've run a series of stories explaining the rule and the segregation patterns that still exist in the U.S. — and how they came to be. They are all collected here.

Obama administration to unveil major new rules targeting segregation across U.S.

The administration called the move “historic,” but conservatives have decried it as “social engineering."

White views on segregation have long lagged behind the law

Twenty-eight percent of whites still say they'd prefer a law allowing homeowners to decide for themselves who to sell to, even if they would rather not sell to blacks.

America can’t talk about segregation today if we can’t say how it was created in the past

A 1968 national report said what is much harder to say today: White society helped create the ghetto.

How railroads, highways and other man-made lines racially divide America’s cities

Stark maps of the power of infrastructure itself to segregate.

How race still influences where we chose to live

The sticky role of preference in preserving segregation — and how to change it.