Fort Sauerkraut was built in Hebron, North Dakota in November of 1892.
The city of Hebron was only founded in 1885, by two recent German immigrants, Charles Krauth and Ferdinand Leutz. These men were representatives of the Germans from Russia, a group of Germans that had lived in Russian colonies along the Volga River since the 1760's.
The city grew slowly over the next few years, drawing in more German immigrants who homesteaded the surrounding prairie. This growth was also made possible by the end of the Dakota Sioux's rebellion against being forced into reservations. Custer and his ilk had died in their skirmish less than 20 years previous, and incidents occurred every few years, until about 1880.
Then, in November of 1892, rumor spread that a large group of Dakota had "broken out" and were "ready to start mischief". This sent the immigrants into a flight of panic to protect themselves, and their community. The hurriedly decided to build a fort.
Construction started immediately, about 200 yards north of the railroad tracks. Materials with which to construct the fort were limited, due to the overwhelming lack of trees in the northern plains. The short notice prevented them from ordering lumber ahead of time. Thus, they built the fort from the only material they had: Sod.
The sod fort was christened Fort Sauerkraut in tribute to the settlers' shared German heritage, and was occupied for about two or three weeks. Finally, the rumor that had started all the uproar was shown to be false, everyone returned to their regular lives, and the fort was abandoned.
The structure stood for a few years more before it was either destroyed or fell apart on its own, the records as far as that are hazy. However, the story of Fort Sauerkraut and the early settlers of Hebron still remain, and a replica fort will be built on the same site, just west of the St. John's Church cemetery, this summer.
Sources: The Hebron Herald and my grandfather, head of the Hebron Historical Society.