This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Son Byong-hui became the most prominent of the thirty three national leaders who signed Korea's Declaration of Independence on March 1, 1919, an event Cheondogyo's own members helped organize in large numbers, drawing on the institutional reach his 1905 reorganization had built fourteen years earlier. He was the first to sign and among those who publicly read the declaration aloud, placing him at the visible centre of the movement's single most consequential day.
Japanese colonial authorities responded by arresting tens of thousands of demonstrators as they suppressed the movement, and Son was arrested along with them despite his prominence rather than being spared it on account of his standing. He remained imprisoned until his health failed under confinement, a decline the historical record attributes directly to the conditions of his detention.
He died in 1922, not long after being released on medical grounds, having never abandoned Cheondogyo's leadership even under imprisonment. His death, a direct consequence of colonial custody rather than a natural end to a long retirement, ties the religious reorganization he led in 1905 directly to the political consequence he suffered for it fourteen years later.