At age 19, the future writer moved to the United States to become a journalist, settling in Cincinnati, Ohio followed by New Orleans, Louisiana. There, he married a black woman named Mattie Foley (not only scandalous but also illegal at the time). Hearn described New Orleans as a snapshot of its former glory, writing of it in terms of decay and disuse:
There is much crumbling of wood-work, looseness of jointing, ulcerous exposure of the brick skeleton where plaster has rotted away in patches from piazza pillars and from the ribs of archways. Grass struggles up between the flagging; microscopic fungi patch the wall surfaces with sickly green. The semitropical forces of nature in the South are mighty to destroy the work of man. Dismally romantic... This ruin has a veritable classic dignity — a melancholy that is antique.
Ultimately, he settled in Japan, where he remarried and took the name Koizumi Yakumo. The trip inspired his book, Glimpses of Unfamiliar Japan, in 1894. The book begins with his justification for writing it:
"Do not fail to write down your first impressions as soon as possible," said a kind English professor whom I had the pleasure of meeting soon after my arrival in Japan: "they are evanescent, you know; they will never come to you again, once they have faded out; and yet of all the strange sensations you may receive in this country you will feel none so charming as these." ...I neglected the friendly advice, in spite of all resolves to obey it: I could not, in those first weeks, resign myself to remain indoors and write, while there was yet so much to see and hear and feel in the sun-steeped ways of the wonderful Japanese city. Still, even could I revive all the lost sensations of those first experiences, I doubt if I could express and fix them in words. The first charm of Japan is intangible and volatile as a perfume.