In the current digital technology era, there are many modern methods and techniques applied in historical research, in which, Text Mining techniques are approached more and more popularly in historical documents. Text Mining technique is combined with ATLAS.ti, a German software to exploit important values in historical documents. This paper presents the research on Dinh Dien Cai San, a strategic settlement area in the Mekong Delta of Vietnam from 1957 to 1963, through the exploitation of Vietnam national archival documents by ATLAS.ti software. The research results do not only provide important historical documents on settlement activities and agricultural production in Dinh Dien Cai San but also become an important basis for the orientation of socio-economic development in Can Tho City nowadays.