Your article is amazing! I carve pumpkins cause it's fun and I'm superstitious... so it stays outside until the true day of All Hallow's Eve is passed. Either way great article!
I'm sorry if this is a bit hyper-critical, but from a European perspective, this article is a little 'off'.
Firstly, It's a wee bit harsh saying that no-one had heard of All Hallows' Eve before the Great Famine (1845-1852, by the way. I assume this is the one you meant as there were two other Irish famines in the century surrounding this one.) Certainly the Celtic races, and surely most European countries would have known about it. That's a significant population to discount as 'no one'. I take it you actually meant to say 'no one in America had even heard of it,' which is also hardly believable. They probably just didn't celebrate it as fully as they did later, considering the other immigrants that had made up the population from the 17th century.
The tradition of souling is an medieval English one, which took place on All Hallows' Day, resembling closely the trick-or-treating of today. Soulers would be given 'soul cakes' representing a soul in purgatory when they approached houses. Every cake eaten was a soul freed to Heaven. They would carry carved turnip lanterns when they went souling, probably because they were too poor too afford a proper lantern.
The carving of pumpkins, however, is in fact an American tradition to do with the harvest, that later adapted itself to Hallowe'en, possibly something to do with the influx of Irish immigrants, I'm not sure, as it was at the time of the mass immigration in the mid 19'th century, and a little later that the change occured.
And, by the way, it's spelt 'Samhain' (pronounced sar-win). It's the first key celebration of the Celtic year, followed by Imbolc, Bealtaine and Lughnasadh.
Another thing why they use pumpkins is because when the Irish (it originated in Ireland) moved to the Americas after the potato famine, radishes weren't widely available, but pumpkins were so that's where that came from.
I don't usually read articles but the title of this one intrigued me. I was familiar with bits of the history already but your narrative style kept me reading anyway and it was worth it :) It's written really nicely and has a lot of perspective- it's nice to read something that tells a different side to halloween to what is typically believed :)