In April 1862 "De Soto" was busy ferrying troops to evacuate the area near Island Number 10 on the Mississippi River and was used, under a flag of truce, to communicate with Union gunboats. On 7 April 1862 she carried Confederate officers who surrendered possession of Island Number 10 to Flag Officer Andrew Hull Foote. It was at night, and "De Soto" approached cautiously, giving four blasts of her whistle, repeatedly, until answered, whereupon Federal officers came on board to accept the surrender.