There is also this Variation, which is somewhere between both our versions that i found on wikipedia.org:
For want of a nail a horseshoe was lost,
for want of a horseshoe a horse went lame,
for want of a horse a rider never got through,
for want of a rider a message never arrived,
for want of a message an army was never sent,
for want of an army a battle was lost,
for want of a battle a war was lost,
for want of a war a kingdom fell,
and all for want of a nail.
Like I said, there are several different versions.
The version I learned was from Mr Roger Figge, (Fig-ee), one of the finest history professors I have ever met. He inspired a D average student to learn about the world we came from.