Early in the US Civil War, Confederates captured Union shipyards at Norfolk, Virginia and Pensacola, Florida. As the war moved along these gains were thwarted by the Union.
Having to recruit from a much smaller population. Success of the Union naval blockade.
The US Navy yard at Norfolk, Virginia was seized by the Confederates, yielding many naval cannon which they used for years.
During the Civil War, the goals for the Union were to create a naval blockade on southern ports, gain control of the Mississippi River, and take over the Confederates capitol of Richmond, Virginia.
Yes, there were naval battles; in fact, the first ironclad ships were invented during the Civil War.
The Union navy had naval superiority during the Civil War.
Naval battle
Naval battle
Fort Sumter
The Battle of Hampton Roads.
The Naval blockade
First a Naval blockade, which was generally successful. Then the Emancipation Proclamation (effective January 1863), which made it impossible for foreign countries to aid the Confederates without looking pro-slavery. This was also successful.
The Confederacy's capture of Fort Sumter led to the Naval blockade.