The most reason why fukujinzuke had become popular nationwide rapidly from the Meiji period as a national food, is that fukujinzuke was introduced by the Imperial Army and Navy as a subsidiary food for rations in barracks and combat, and the retired soldiers brought the taste of fukujinzuke back to their homes, then spread.
明治時代以降、国民食として短期間に全国に広まった最大の理由は、帝国陸海軍の隊内食・戦闘食の副食として採用されたため、兵役終了後の元兵士達により、その味が全国の家庭に持ち帰られ、浸透した。