This is a comedy about a POW camp in WW2 Germany.
Hogan is played by ill fated Bob Crane, who wise cracks his way through the series, making fools of the Germans.
To be honest, this series is very racist against German (pale, fair haired, European) males, while being accepting of German females.
That was the standard racism and neo Nazi Hollywood ideology of the seventies. The show actually paid homage to Adolf and Eva by declaring women to be fair and blond, while sending German males to die in war.
That was the American ideology of the late sixties up through the eighties, and it's not possible to watch movies or TV shows from that era without noticing it.
This particular show was boring when I was younger, but actually had some wit to it that is noticed more by older people.
It helps that every episode is totally ridiculous and can't be taken seriously.