After the Battle of Sekigahara in 1600, the Uesugi were transferred from Aizu to Yonezawa, their holdings reduced to 300,000 koku. Yonezawa Castle became the new seat of the domain, and from here Kanetsugu, as chief administrator, directed the planning of the castle town, flood-control works along the Mogami River, and the promotion of industries such as ramie weaving. His achievement in sustaining the entire retainer corps and building the foundations of the domain's later prosperity is inseparable from the history of Yonezawa Castle.