Isekai Kenkokuki

The protagonist after an accident is "reborn" in another world as an abandoned child and is entrusted with other abandoned children like him. In order to survive, using vast knowledge of previous world, he teaches them new things...starting from how to prepare and cultivate a land. Little by little, orphans gathered, and upon hearing rumors of a new village, others began to migrate. The group that had been nothing but children had become a village before anyone have realized. And then various countries in the surroundings started to have an eye on it…

This is the epic tale of the man who would later be known as the Divine Emperor.

(Source: Shousetsuka ni Narou, translated)