I was reading the book "Outwitting History" this author ...

Aaron Lansky

... who set out to save Yiddish literature, and succeeded.

In his book, he recounts the time when he got a call that Newark, New Jersey's public library was indiscriminately culling books, especially a large and valuable collection of Yiddish books. He saved most, but at least two shelves worth had gone to a dumpster.

Of interest to Esperantists was this follow-up:

Alongside the Yiddish books was an equally dismaying sight: an extraordinary collection of books in Esperanto, the "universal language" invented in Warsaw by a Yiddish-speaking Jew named L. L. Zamenhof. It is said that at the international Esperanto conferences held each year in Warsaw before the Second World War, papers were delivered in Esperanto but conversation in the halls took place in Yiddish - the only truly international language the delegates shared in common. From these shelves, too, books were missing, as though to mock the enlightened dream that had created them.

The administrator assured us that she was making arrangements for someone else to save the Esperanto collection ...

Two things of interest:

1) The delegates to the pre-WW2 conferences spoke Yiddish. Interesting. At the very least, this indicates Esperanto activists at that time were very predominently Jewish.

2) I don't suppose anyone knows what became of Newark's Esperanto collection? This incident isn't dated clearly in the book, but seems to be from the early-to-mid 1980s.

I've heard this thing before about the Yiddish, and it has always been from people involved in Yiddish. I've often wondered if it's really true, but the more I thought about it, I eventually came to the conclusion that the story must be apocryphal, or else an exaggeration (from someone who heard a few people speaking Yiddish and overstated the extent of it).

Let's put it this way - if a very significant proportion of early Esperantists were Yiddish-speaking Jews, you would expect that a very significant proportion of the early luminaries of Esperanto were Yiddish-speaking Jews, right?

But of the early luminaries of Esperanto, I guess some of them were Jewish, but most were probably not. I don't see an abundance of Jewish-sounding names. If Yiddish were indeed so predominant among early Esperanto speakers, I find it hard to believe that almost none of these Yiddish-speaking Esperantists ever reached a position of any prominence in the movement.

erinja:If Yiddish were indeed so predominant among early Esperanto speakers, I find it hard to believe that almost none of these Yiddish-speaking Esperantists ever reached a position of any prominence in the movement.

By "early" do you mean before or after WW2? They might have all (or mostly) died in the Holocaust. Some of Zamenhof's family did.

(Now I'm wondering if early Volapukists were all ultramontane Catholics like Schleyer ...)

Bruso:

erinja:If Yiddish were indeed so predominant among early Esperanto speakers, I find it hard to believe that almost none of these Yiddish-speaking Esperantists ever reached a position of any prominence in the movement.

By "early" do you mean before or after WW2? They might have all (or mostly) died in the Holocaust. Some of Zamenhof's family did.

(Now I'm wondering if early Volapukists were all ultramontane Catholics like Schleyer ...)

Early is before WW2. Esperanto was already well established by the time the war rolled around.