What did Japanese look like before the spelling reform?

Or “language reform” or whatever you want to call it. I understand that pre-reform Japanese had a lot more Kanji, including some of the particles usually being written in Kanji. Is pre-reform writing readable (with some effort) to modern educated native speakers, similar to me reading non-cleaned up Chaucer? Or is it so different as to be nigh-unreadable without being explicitly educated in it? As for the particles, why did they decide to use (keep?) は for “wa” and へ for “e”, but only as particles (for non-speakers, in all other contexts those characters are “ha” and “he” respectively)? Finally, why did they keep ゐ/ヰ (i/wi) and ゑ/ヱ (e/we) around, despite having apparently no use? I recall learning those two in Japanese class when we learned katakana/hiragana (just on a lark, they told us not to actually bother memorizing them; see also: katakana wo/o ヲ, which as far as I can tell is only used for stylistic reasons and even then rarely).

For the pedantic, I’m specifically referring to the immediately post-WWII reform (which I believe was the most radical reform), I understand that things have changed a bit since then (especially some older Kanji being reintroduced) and I also know that attempts at written word reform have been going since the mid to late Meiji era.

Bonus question: How difficult was it for people to switch over? Was it a significant hurdle to get people to relearn/write in the new way?

I’d like to know more about this topic too. The only point I can contribute is that there’s a great example of one of the archaic characters in a national brand:Yebisu Beer. (Scroll down for a lovely example of pre-reform writing. The katakana on the wooden box is written right-to-left.)

If you’re talking about WWII era texts, those are trivially easy for a modern reader. First, the reform of kanji was much, much more conservative than the change from traditional to simplified characters in China. Traditional forms of common characters are still seen, mostly to give a certain archaic feel. For instance (and on completely opposite sides of the cultural spectrum), the rock band Kishidan[/ur] (氣志團 instead of 気志団) and the literary magazine [url=http://www.bunshun.co.jp/]Bungei Shunju (文藝春秋 instead of 文芸春秋). Even for less common characters, since there was an effort to preserve strokes in the simplification, you can easily figure out what they are from context.

Changes in the use of kana are also fairly trivial and even without much prior knowledge (which native speakers have) you could easily figure out the rules of the old spelling quickly enough. Here are some example of spellings that were updated to be more phonetically accurate:

ゐ -> い
ゑ -> え
を -> お (except when used as a particle where it remains)
は -> わ (except when used as a particle where it remains)
ひ -> い
ふ -> う
へ -> え (except when used as a particle where it remains)
ほ -> お

The two three characters are now fully archaic, and the third is only used as a particle. The latter characters used to do double duty, and were kept only to represent sounds beginning with /h/ (again, except for は when used as particle.)

Originally, the idea was to have a system that was fully and perfectly phonetic. は,へ and を kept their old readings when used as particles because in this role they were seen as being more symbolic than phonetic. However, this was apparently a contentious issue at the time.

For the record, here’s an excerpt from a 1942 text by linguist Shinkichi Hashimoto quoted on the Japanese Wikipedia:

Changing it to modern forms would give:

The most difficult expression is possibly 「かやうな」, but it’s really the expression itself that’s archaic. Writing 「そうして」as 「さうして」is so common that after the first two or three times, you don’t even notice.

I live in Taiwan which still uses the traditional characters and it’s much easier to switch over than it would be to the simplified characters used in China. Some characters take a little bit to get used to, but it’s not a huge deal. I guess it would be like getting used to new standardized spelling. It’s much easier to read than to remember how to write them. I suspect that it would have taken a while for the older use to die out and replaced by the newer characters.