The flag of Nazi-ruled America of 1962 in “The Man in the High Castle” has red and white stripes and a swastika on a field of blue. But even more chilling is how fascism has stamped itself upon American popular culture.

People still go to Rock Hudson movies, but they open with Nazi propaganda newsreels. There are cop shows on TV; one is about the adventures of the “Reich Patrol.” Times Square is still riotous and noisy, but one blazing sign reads “Work Will Set You Free,” the slogan — in German, “Arbeit Macht Frei” — that hung on the gates of Auschwitz.

In “The Man in the High Castle,” the unsettling, if uneven, alternative-history thriller whose 10-episode first season begins Friday on Amazon Prime, fascism has not simply conquered America. It has insinuated itself, with disturbing ease, into America’s DNA.

Frank Spotnitz (“The X-Files”) adapted the series, with significant changes, from the Philip K. Dick novel of the same name. In this world, Hitler (still alive, but feeble) got the atomic bomb and dropped it on Washington. The Axis partitioned North America: the Greater Nazi Reich in the East, the Japanese Pacific States in the West and a no-man’s-land buffer zone in the Rocky Mountains.