While the board in New York gave him the green light, and Allen departed for Korea while leaving his wife in Shanghai. He arrived at Jemulpo on September 20, 1884. Thus, in the four-millennium Korean history, Allen arrived in Korea as the first Protestant missionary (albeit his religious status had to remain hidden) and the era of Protestant missions commenced in Korea. Two days after arriving at Jemulpo, he rode a donkey with a Chinese language teacher that came with him from Shanghai and entered Seoul.
Source: wiktionary