There is no indication where Reaves group was exchanged following their parole at Ship Island which would have been conducted somewhere on the mainland controlled by the Confederate government, not on the island.
William McDaniel Reaves, Wilcox County, Alabama, Private, Company F, 21st Alabama Infantry, was captured at Fort Gaines August 8, 1864, received at Ship Island, Mississippi, from New Orleans. La., October 25, 1864, exchanged January 4, 1865. He received his parole with other members of his command at Meridian Miss, May 13, 1865.
The 21st was surrendered at Cuba Station, Sumter County, 6 May 1865, and paroled at Meridian, MS, about 250 strong.
http://www.scvsemmes.org/21st-alabama-infantry-regiment.html
Cuba Station, located approximately midway between Demopolis and Meridian, Ala. on US 80. Apparently a Parole Camp.*
Those captured at Blakely, on April 9, 1865 were received at Ship Island, MS on April 15. They were subsequently transferred to Vicksburg for exchange on May 1 and were exchanged at Camp Townsend, Miss., May 6, 1865.
See: Ship Island, Mississippi: Rosters and History of the Civil War Prison
By Theresa Arnold-Scriber, Terry G. Scriber
* CAMP CUBA STATION (near present-day Cuba, AL)
about one mile west of town. Cuba was a parole point at war's end, because of its close proximity to Meridian (HQ). Thousands of Confederate soldiers, especially artillerymen, were camped, surrendered and paroled at Cuba Station.
http://www.treasurenet.com/forums/alabama/96813-alabama-cw-camp-list.html
……….
With the evacuation of Mobile on April 12, the regiment retreated up the Mobile and Ohio Railroad with General Taylor’s command. Resistance in Virginia and North Carolina having collapsed, the 210 soldiers in the regiment surrendered on May 4 at Cuba Station, Alabama, in Sumter County. The men of the Twenty-first Alabama were paroled at Meridian, Mississippi, on May 10,
From that Terrible Field: Civil War Letters of James M. Williams, 21st Alabama Infantry https://books.google.com/books?id=Fhg4WeaLf04C&pg=PR15&lpg=PR15&dq=Cuba+Station,+Alabama+Parole+camp&source=bl&ots=hRNfDPs2cC&sig=5J_31_MPvyAD4RBzrYbSkmaP1U0&hl=en&sa=X&ei=bVV2VZWPHMS2oQTfxICwAg&ved=0CD4Q6AEwBQ#v=onepage&q=Cuba%20Station%2C%20Alabama%20Parole%20camp&f=false