And, at no extra charge:
All the ACP rounds were designed by John Moses Browning. (As best my tired old memory serves.)
.25 ACP, adapted by the Europeans and called 6.25mm
.32 ACP, adapted by the Europeans and called 7.65mm
.380 ACP, adapted by the Europeans and called 9mm [insert European word meaning 'short'; Corto, Kurz or Kurtz, and so on]
.38 ACP, equal to the 9mm Luger and fore runner of the Super .38
.45 ACP
Kymasabe, you've already been answered. "45 Auto", well used by most everyone, is in fact a misnomer. The proper name of the cartridge is .45 ACP. It is sometime referred to as "45 Colt Auto" or "Colt 45 Auto", but those are also popular names rather than actual nomenclature.
But we live in an age where people don't really pay attention to detail and tend to invent their own language.