See post #9 - he was absolutely correct. The .45 schofield is shorter, so the cowboys of the 1880s used to call them .45 long and .45 short, with the Colt being the longer of the two. It was commonly called .45Colt or .45Long and eventually just got called .45LongColt.
Likewise, when Colt came out with the .45ACP (Auto Colt Pistol - which was also shorter than the .45Colt), the .45 Long Colt again made sense to differentiate the 2 rounds.
Being that guns are my livelihood, I am a tad anal about proper nomenclature.