Assigned to the Home Squadron as flagship, "Roanoke" transported the American filibuster and former President of Nicaragua, William Walker, and his men back to the United States from Aspinwall, Colombia, (now called Colón, Panamá). "Roanoke" arrived on 4 August and the ship was decommissioned at the Boston Navy Yard on 24 September 1857. Recommissioned on almost a year later on 18 August 1858, "Roanoke" resumed her duties as flagship of the Home Squadron. For over a year, she was stationed at Aspinwall awaiting the arrival of the first Japanese embassy to the United States to ratify the 1858 Treaty of Amity and Commerce. They reached Aspinwall on 25 April 1860 and "Roanoke" reached Hampton Roads on 12 May 1860 with the delegation and was again decommissioned.