Together with Jo In-hwan, An Yong-un, Yi Dae-hui and Jo Taek-seung, Yi Jeong-hwan helped plan the March 13, 1919 independence demonstration at Sinchang market in Bukcheong. Kim Byeong-hae and the crowd marched for about four hours carrying a flag reading "Long live the independence of the Korean nation," and arrests of the organizers, including Jo In-hwan, began that same night.