Approximately three thousand American citizens of Japanese descent, known as Nisei, were living in Hiroshima on that day, but there is no evidence that the crew members of the Enola Gay had any knowledge of their presence. The annual figure for emigrants from Hiroshima Prefecture ranged as high as seven thousand. The majority of Hiroshima emigrants originated from the city of Hiroshima itself, the downstream areas of the Ota River, and the western shore of Hiroshima Bay– all of which were heavily engaged in the cultivation of cotton. Because many Issei parents reported the birth of their children to the local government offices in their native villages or towns in Japan, quite a few Nisei possessed dual citizenship. The Tatsuta maru, which sailed for Japan in August 1941, was crowded with Issei planning to visit their hometowns and Nisei who were looking forward to seeing the country of their ancestry for the first time.