The school shown is New Urecht High School, where Gabe Kaplan was a student.
Alex: (to Kotter) In your socks with a pound of lox!
Freddie: This coat was worn at the famous Lincoln-Douglas debate.
Kotter: This coat was worn at the famous Lincoln-Douglas debate?
Freddie: I wore this coat when my father, Lincoln, beat the daylights out of my brother, Douglas!
Kotter: Just think of a debate as sort of a, um, rumble with words.
Vinnie: You mean like, 'Up your nose with a garden hose?'
Kotter: (seeing the mural)What do you call this anyway, Moonlight Over Garbage?
Vinnie: (to Todd) Off my case, potato face!