Realistically, our Highland ancestors probably wore one form of the kilt or another. Our Border and Lowland ancestors probably did not wear one, and until Sir Walter Scott's grand event in 1822, they probably considered a kilt to be rather barbaric. It was more normal for gentlemen to wear trews (trousers).
In the evolution of the kilt, we find that it came from an area where trousers would have been perpetually wet. The breacan faile (large kilt) provided the Highlander with a warm upper garment as well. Remember that it was just a big blanket and was used for many purposes. The faile beag (small kilt) kept the kilt but made it easier to wear. Several authors suggest that the very people who decried the wearing of Highland dress -- the victors at Culloden Moor in 1745 -- are the ones who promote its wearing by Scots world wide. Whatever the situation, wear your kilt with pride!
-- by Russ Henderson