I have been doing some research on the American Civil War. So far I have determined that no country interferred or helped with one exception. From Wikipedia: "British investors built small, very fast, steam-driven blockade runners that traded arms and luxuries brought in from Britain through Bermuda, Cuba, and the Bahamas in return for high-priced cotton. The ships were so small that only a small amount of cotton went out. When the Union Navy seized a blockade runner, the ship and cargo were condemned as a Prize of war and sold with the proceeds given to the Navy sailors; the captured crewmen were mostly British and they were simply released." 'Nuf Said?
Emily, You might consider emailing the SC Rec Center and asking if they ever have trips to DC. If they don't suggest they do so. There are travel agencies in SC that might have them. Google travel agencies in Sun City and ask.