Later Sinosphere maps produced by Chinese cartographers that focused on Northern Vietnam continued to show its connections to southern China. The following two maps show this connection. The first map is from 1870, a decade and a half before the Sino-French war of 1884 and 1885. In 1870, the Qing court still occupied a privileged position vis-a-vis the delta and the Nguyen Court. It shows a gridded space as Chinese mapmakers addressed European cartographic conventions. The second map is from sometime between 1885 and 1890. This map comes from after the Sino-French war. It shows a similar Sinosphere imaginary even after the Red River Delta had fallen under French control and been incorporated into the new political entity of Indochina. Both maps use the term "Yuë(h) Nan," or southern Yuëh, a neutral term, rather than the pejorative "An Nan." As Richard Smith suggests, these maps hint at the "khi" or "chi" lines linking northern Vietnam to southern China.
These maps also show northern Vietnam in national and borderland geographies, which are shown on separate pages.
The final map included here is of “Đại Nam,” or the great south, compiled under Minh Mạng, the second emperor of the Nguyen Dynasty, in 1834. It shows a “Đại Nam” unified under the Nguyen Dynasty that has a geographic extent close to present day Vietnam. For our purposes, what is interesting is the orientation and language of the map. First, it is oriented as if looking from a boat onto land. China sits to the right of Đại Nam. Second, place names are written using Chinese characters. Third, and in a related way, this map uses the name "Đại Nam" rather than "Yuëh Nan." The former name places emphasis on being the great south, rather than being the Yuëh. Either way, both names reflect the importance of the north, or China, in Vietnamese thought.
These two details show the ways that the Nguyen dynasty viewed itself as part of the Sinosphere. Minh Mạng in particular drew from neo-Confucian thought to govern his realm. He ruled from 1820 to his death in 1841 and in that time instituted a number of reforms that spread neo-Confucian ideology and consolidated his hold on the bureaucracy. This map was produced for himself and his own subjects, showing the intended extent of his rule. It includes the newly settled Mekong Delta, where Minh Mạng constructed a canal that was meant to improve transport and to create a political border with the kingdom of Cambodia. Whereas the Cambodian kings had ruled over the Mekong Delta and its largely Khmer population, this border put almost all of the Delta under Nguyen rule. As the maps orientation and toponyms suggest, this map was also produced for a Chinese audience. It shows Nguyen rule over islands that are now called the Spratleys and Paracels and this map has been used as evidence to contest Chinese control of these islands.
Compare the historic maps above to the Google map equivalents of looking west (e.g. from a ship) and south (e.g. from China) below. You can also refer to the "Tabula geographica imperii anamitici" published in 1838 and included in the page on northern Vietnam as part of a national geography.