Can't shed any light on the event or the recipient, but I believe the Richland Light Dragoons was Wade Hampton's old company that he commanded at one time.
Thomas W. Radcliffe (1812–1870) was a jeweler and watchmaker in Columbia, and likely was the source of the silver cup. After the outbreak of war, he entered active duty at Columbia as captain of Co. A, 15th SC Infantry, on 5 September 1861, and served on the South Carolina coast. He was appointed major on 22 October 1861, but resigned for health reasons in November 1861, before accepting the promotion. He subsequently served as a drill master at the camp of instruction at Lightwood Knot Springs near Columbia, and was appointed captain and quartermaster there on 26 November 1862. On 20 August 1863, he was appointed major, and was last reported at that station in October 1864. He died in Columbia on 14 Apr 1870, and is buried in Elmwood Cemetery. His son, Sergeant Thomas Radcliffe, Jr., Co. C, 2d SC Cavalry, was killed at Madison C.H., VA, on 22 Sep 1863.
Hope this helps a little.
To Join the Company of Military Historians click here