The term Union was derived because the states were united and determined to leave one form of government to begin a government for protection of the members and their joint concerns. Maybe the word Union would have implied the same thing as it is in the marriage ceremony. Joined together. Even if that were the case, there were implied limits as to the power of the ‘Union’. So possibly the ConFEDERATion of states would have been more correct as to the real intent. Here we see the term ‘Federal’.
Either way, it was still the central government. The old “United We Stand, Divided We Fall” rule. [I’m hearing that song running in my head] had to be explicit or the house of cards would come down.
It worked well for a number of years.
When the 13 states, or if you wish to say the 11 and 2 partial states, took themselves out of that ‘Union’ or ‘Federation’ the original was smaller but the same rules to their existence applied. The states that left were the ConFEDERATion of states also. It just was called the Confederacy.

I can see the importance of the usage of Federal or Union for some applications but during the time frame of 1861-1865 it meant two different things to two different entities. I cannot see how using the term Federal is in any way making something bigger and better or more powerful than another. Neither is Union. They are interchangeable to me.

After 1865, I do agree on your statement that the term Union made the rest of the world take notice and any little schemes they may have been thinking were not going to fly. After 1865, we were a Union. We remained a Union. Even though it took quite a long time for some from the former Confederate States to adjust to it. A ‘United’ front on the rest of the world was the best weapon we had. We were together for both World Wars, Korea, Viet Nam, the Gulf War, Iraq and Afghanistan.

Until the last couple of years, I never believed it would be challenged from within again but I’m not so sure now. The Central part of the Union has again over run its limits and gone into the states area of control or decision making. In doing so, I believe we are getting a much clearer picture of just why the Confederate States did what was then unthinkable. IF there is a next time, it won’t be as geographically simple.

Pam