After Kenshin's death, the Uesugi Clan was headed by his adopted son, Kagekatsu UESUGI, who was no threat to Nobunaga, and their power declined due to family trouble called the Otate War, therefore it can be said that the death of Kenshin facilitated Nobunaga's Tenka-fubu (a slogan meaning that the samurai rules the whole world).
また、上杉氏も謙信没後は養子の上杉景勝が継いだが、景勝は信長の敵ではなく、また御館の乱という御家騒動から勢力が減退したため、謙信死去により、信長の天下布武はさらに前進したといえる。