His brigade became part of the expedition against Fort Fisher in December 1864. Curtis' brigade was among the few troops to go ashore yet the first attack against Fort Fisher was defeated. He took part in the second attack in January 1865, in which his brigade played a key role in the Union victory. During the fighting a suggestion of entrenching reached Curtis. He angrily grabbed a handful of shovels and threw them over the traverse shouting "Dig Johnnies! I'm coming for you!" Curtis made good on his promise and continued the attack. He was wounded at the head of his brigade and received a full promotion to brigadier general of volunteers and was also received the Medal of Honor. He remained in the army until January 1866, receiving a brevet to major general of volunteers on March 13, 1865.