It was essentially a naval war.

[wausaubob]

All US cities were either ocean ports, river towns or service by canals.

US military capacity was based on ship building capacity, with the main yards in Portsmouth, ME, Boston, Brooklyn, and Philadelphia. The main research station was in Washington, DC.

Men and material moved by the more efficient means of steamship transport, whenever possible.
https://www.jstor.org/stable/1888813?seq=4#metadata_info_tab_contents See page 327.

Although sea power was written down in the United States between 1865 and 1900, while railroads gain ascendancy, that was an inaccurate rendition of the Civil War.
The three biggest operations were Farragut's capture of New Orleans, Grant and Porter's reduction of Vicksburg, and Grant's siege of Richmond based on his water borne logistics which turned City Point into a major shipping center.
Oddly even Sherman's march was to the sea, occupied by the US navy.

 

[wausaubob]

The great mechanical engineer, Benjamin F. Isherwood, who knew what to build and what to buy, and the self taught industrial engineer, James Eads, who knew how to build stuff, quietly supplied the science necessary to make the steam ships and steamboats the dominant weapons of the Civil War.

 

[wausaubob]

There were only a limited number of places on the Ohio and Mississippi Rivers that build riverboats. While the Confederates were sinking a few US navy and merchant ships, the US was capturing and closing the Confederate ports.