Please, I would like some clarification on some of the unit designations I have seen at various sources.

What is the distinction between Heavy Artilery, Light Artilery, and Horse Artilery? I assume Heavy Artilery would designate Artilery that would be located at fixed locations such as forts, etc. but have noted that in some battle reports there is mention of Heavy Artilery Units being involved where there were no fixed permanent fortications in this particular location.

It is also noted that in some instances Artilery Units are designated as "Independent"; primarily in Union Forces. In other instances Units bear the name of an individual. I assume units designated with an individual's name was raised by that particular individual, but I would like to know from where the designation "Independent Battery" orginates.

In many battle reports I find that the units involved are indicated as being from a certain state; i.e. 1st Ohio, 2nd Ga., 9th Penn, etc. However, in a few instances units are designated as "United States".Does the designation "United States" indicate that these Army units were established before the beginning of the Civil War and retained their original designation to distinguish them from units raised by individual states?

I also note in a few instances that Calvary Units as well as infantry units are indicated as engaging River Gun Boats.

Does this circumstance involve infantry and unmounted calvary attempting to board the gun boats or was Light Artilery used by the land forces to attack gun boats?

This post asks lots of questions...maybe the answers are general knowledge to most..but not to me. Any help will be appreciated.