In 1842, the Treaty of Nanking opened Shanghai as a treaty port. In 1899, of what is now the south of modern Yangpu District was partitioned to become part of the International Settlement. Factories were constructed soon after in the area, especially along Yangshupu Road. Textile, paper-making, and shipbuilding industries were established by the early 20th century in what was then organized as part of Hongkew (now Hongkou). In 1929, the Wujiaochang farmers' market ("Pentagon Plaza") was constructed in the north. Later, during the Japanese occupation from 1937 to 1945, barracks and houses were built in the area. The inland part of the former International Settlement in the area made up part of the Shanghai Ghetto. In December 1944, Yangshupu District was established with an area of .