The chain by which his teaching left Burma is short and well documented. He taught a farmer named Saya Thetgyi, who became a lay meditation teacher. Saya Thetgyi taught U Ba Khin, an accountant who rose to be accountant general of newly independent Burma and who taught meditation in his government office. U Ba Khin taught S. N. Goenka, a Burmese-Indian businessman who moved to India in 1969 and began giving ten-day courses. Those courses, deliberately stripped of anything that would read as sectarian, now run in more than a hundred countries.
Two features of the modern form come straight from this line: the fixed-length residential retreat as the unit of practice, and the presentation of the technique as a method anyone may use rather than as a Buddhist observance. Both were shaped by the needs of laypeople with jobs.
How to read all of this is genuinely contested. One reading, argued at length by Erik Braun, holds that Ledi Sayadaw was working within a deep Burmese textual tradition and responding intelligently to a real crisis, so the movement is a development of Theravada rather than a departure from it. Another, associated with Robert Sharf, holds that the modern emphasis on personal meditative experience as the heart of Buddhism is itself a modern construction, shaped by encounter with Western categories and by apologetic need, and that traditional Theravada looked very different. The atlas records the disagreement rather than resolving it.