War and battle brought fame, what would peace bring? Most likely much work. He decided to visit every corner of his kingdom, and to educate his people. Nothing was more difficult than to convince the Prussian farmer to start with the planting of the potato. A lot of voices were raised in opposition by the farmers of the Mark Brandenburg. They called the potato a health threatening, poisonous bulb. Frederick involved the Church, where the clergy included the blessing of this new fruit in their sermons. Where this failed, he sent riders out into the countryside to oversee the planting.

In the beginning of 1747 the construction of the port of Swinemuende began. At the same time the building of the Finow canal was under way, which would connect the two rivers of Berlin, Havel and Spree with the river Oder. The canal at Plauen would eventually do the same in the west: to connect the river Havel with the Elbe. On July 8, 1747 the work began to cultivate the land at the Oder river. Frederick also started to bring in Settlers to the thinly populated areas from other regions of Germany. The newcomers received free wood to build a small house, animals and seeds for their land, and an exemption from taxes and military service for several years. Between 1740 and 1755 the population of the old Prussian provinces grew by 20%.

Frederick was delighted with his new summer residence in Potsdam. 250 years have passed, and this beautiful little Palace, with Millions of visitors from all over the world, still has no equal anywhere. A vineyard slopes down towards the lake, and every year from May to November Frederick was in residence at Sans Souci. This was his Rheinsberg, but with one exception: It was his alone, Elisabeth Christine remained first at the big Palace in Berlin, and later she took up residence at a smaller Palace in Schoenhausen near Berlin.

Theodor Fontane wrote a century later "Prussia was built from Potsdam, but from Sans Souci came the light that radiated throughout the land."