In its broadest sense, the Eastern District of Taipei is the whole region east of Fuxing South Road.
During Japanese rule, the development of a downtown was only extended eastward to the Horikawa Drainage Channel (present day Xinsheng Road).
The situation changed in the early 1940s when the Kuomintang retreated to Taiwan with 2 million people.
These factors lead to a sharp increase in population, causing overpopulation in the Western District.
Furthermore, the Tamsui River hindered the expansion of Taipei City to develop in a westerly direction.