Following the American Civil War, the Army and Navy were unsupportive of each other at either the planning or operational level; thus the Joint Board, acting as an "advisory committee", was created to plan joint operations and resolve problems of common rivalry between the two services.
The American Civil War (also known by other names) was a civil war in the United States from 1861 to 1865, fought between northern states loyal to the Union and southern states that had seceded to form the Confederate States of America. 
