In summer of 1863 Jenkins' brigade of South Carolinians was detached from Longstreet's Corps in the Army of Northern Virginia and left to guard Richmond, therefore missing the Gettysburg Campaign. He was assigned to D.H. Hill's command in the Department of North Carolina during this time. Lee had petitioned for Jenkins' return to the army prior to the Gettysburg Campaign, sending letters to Hill and President Davis; however, Davis turned down his requests. Jenkins and his men also wished for their return to their old place in Longstreet's Corps; he also made multiple requests, but to no avail.
With his brigade sitting around Richmond, Jenkins at least wanted to participate in some action - contribute somewhere. With Fort Wagner at Morris Island under siege from July through September, he then requested to have his brigade transferred to Charleston and proposed a plan to break the siege and relieve the garrison at Wagner (I don't know exactly what that plan comprised of). Davis initially refused and the fort was abandoned in early September.
Just when Jenkins was beginning to believe he would never return to Lee's army and expected an eventual transfer to South Carolina despite the fall of Morris Island, his brigade was returned to Longstreet's Corps and placed in Hood's Division in September 1863 - just prior to the corps' transfer to the Western Theater to reinforce the Army of Tennessee. Longstreet had sent Tige Anderson's brigade of Georgians to Charleston in exchange for Jenkins', one reason being that Jenkins was a good friend and favorite of Longstreet's. It was also thought the Georgians might desert while in their home state without Anderson's leadership, he having been wounded at Gettysburg. Davis had then preferred Jenkins' transfer to Charleston, however it was too late before that could be countermanded.
Jenkins and his men were glad to be back in their old corps and on campaign again, though they would still be separated from Lee's army and now a long way from home, having just thought they would be sent back to South Carolina. Unfortunately for Jenkins, shortly after being sent west his youngest son died at home - he not able to be there to console his pregnant wife and children. His brigade arrived too late to participate at Chickamauga and they would suffer heavy losses in the battle of Wauhatchie at Chattanooga.
The Knoxville Campaign was a harsh and bitter one for Longstreet's command - lots of squabbling among Longstreet and his subordinates, especially between Jenkins and Evander Law over promotion and command of Hood's former division, only to have Charles W. Field promoted to major general and assigned command of the division by February 1864. The campaign took a toll on Jenkins' health, and on his return to Virginia he was suffering from carbuncles. Finally back in the ANV in spring of 1864, Jenkins would unfortunately be killed by friendly fire at the Wilderness on May 6, in the same incident that wounded Longstreet.
I think it's interesting to ponder what if Jenkins had been sent to South Carolina, what his plan for relieving Morris Island entailed and if it would have succeeded. Fort Wagner fell in early September 1863, leading to the closure of Charleston's port, bombardment and destruction of the city and its eventual evacuation. If Davis had consented to Jenkins' first request then he might have made it there before the fort fell. Also, he probably wouldn't have rejoined Longstreet's Corps - at least not by September.
Jenkins' South Carolina Brigade, circa 1863:
1st South Carolina Infantry (Hagood's)
2nd South Carolina Rifles
5th South Carolina Infantry
6th South Carolina Infantry
Palmetto Sharpshooters (Jenkins' own regiment)
Hampton's Legion (now a regiment, with the 4th SC Battalion being consolidated into two companies and added to the Hampton Legion infantry battalion in Nov. 1862)