“I know its source,” I told them, feeling, for once, like intelligent life. “I figured it out—it was Brown versus Board of Education—when the Supreme Court didn’t strike down segregation.”

“That was the result,” said Eddy. “But the seed came before that. It was the failure of Joe.”

“Joe who?” I asked.

“Joe’s not a who, but a what,” Eddy explained. “August 29, 1949. In your previous realities, that was the date of the first successful Soviet atomic bomb test. Code name Joe-1. But in this world Joe-1 failed dismally, and it set the Soviet nuclear program back by ten years.”

Suddenly I wasn’t feeling like intelligent life anymore. “What the hell do Russian nukes have to do with segregation in the United States?”

“Everything’s related,” Ed told me. “All things are interconnected.”

He took the controller, tapped a few keys, and set the QuIRT to English. Then he showed me a list of events that happened in this world, versus ones that happened in the world I came from. As it turns out, in my world, the nuclear arms race with the Soviet Union—better known as the Cold War—was putting a lot of pressure on the United States. Our racial inequalities were well known around the world—and once the Soviets developed nukes, it became a mad scramble to make sure we could get as much of the world on our side as possible. But America’s racial record was an embarrassment. And so, when the matter of segregation reached the Supreme Court, they decided that racial segregation violated the Fourteenth Amendment. Four of the justices voted to end it because it was the right thing to do. The others were swayed by America’s embarrassment factor, and the fear of a nuclear-ready Soviet Union having the moral high ground over us.

But here—in this reality—America hadn’t cared how it looked to the rest of the world in 1954, since a nuclear Russia was not yet on the horizon. And without that pressure, the justices fighting for change were overruled by the ones who were happy to keep things exactly the way they were.