Short answers, pulled from the story.
L. L. Zamenhof, a Jewish ophthalmologist, published the Unua Libro introducing Esperanto in the summer of 1887 in Warsaw. Zamenhof was born in Białystok, then part of the Russian Empire, and designed the language to foster peace and understanding among divided ethnic groups.
Volapük gained a significant following in the late 19th century but collapsed due to internal power struggles and a lack of flexibility. Many adherents switched to Esperanto after the Volapük movement failed, which set the stage for Esperanto to become the most successful international auxiliary language.
Nazi Germany banned the language because Zamenhof was Jewish and targeted Esperantists during the Holocaust. The Soviet Union under Stalin executed, exiled, or imprisoned speakers during the Great Purge, while Francoist Spain suppressed the language due to its association with anarchists and socialists.
By 2018, the number of learners on Duolingo had risen to over 1.36 million after the platform launched a free course in 2015. This growth demonstrates the language's increasing popularity and accessibility through modern technology.
There are estimated to be around 2,000 native speakers who have grown up speaking Esperanto as their first language. This community provides a living example of the language's potential to become a fully functional mother tongue.