The U.S. Military Academy has their own uniform. The U.S. Naval Academy has their own uniform. And the Pontifical North American College (the American seminary in Rome) has their own uniform, too.
It's a rather patriotic garment: red, white and blue (red sash, white collar and blue buttons and piping).
Sadly, with the dynamics of modernism, N.A.C. seminarians are no longer allowed to wear this, their habit, around Rome. I have heard the seminarians complain for years: "If we get caught we'll get kicked out."