Beginning in the mid-19th century, many young men in Kaiping migrated to some countries in North America and Australasia to work at mines, railways and farms. When settling down overseas, expatriate Kaiping people, diligent and brave, never forgot their relatives in Kaiping, to whom they remitted money and wrote letters.

The money helped promote the development of Kaiping, and the letters record the hard lives and affection of these expatriates. In some sense, the money and letters and Kaiping Diaolou and Villages are the two aspects of the cultural heritage—the money and letters are the material and ideological foundations of Kaiping Diaolou and Villages, which, in turn, are the materialisation of the painstaking efforts of the expatriates.