The following link (https://billriski.backpackit.com/pub/1191971) is an excellent source about the rediscovery of Camp Fisher which served as a site for infantry support during a blockade of the Potomac River. Today a golf course in the Montclair area outside of Washington, D.C., Parham wrote from this camp in his fourth letter that we expect every day to hear that Battery set loose on their (Yankee) vessels. Below is a quote from the before mentioned link which describes the economic impact of this blockade.
The batteries affected a logistical nightmare and subsequent economical downturn for the Union Capitol in Washington D.C. as prices of everyday goods like coffee, corn and sugar steadily increased. More importantly, it fostered a negative impact on the Northern sentiment and overall support for the war. For the young Confederacy, it was a capstone event ending this first chapter of the conflict in 1861.