In 1861 it was the industrial north that had the lion's share of weapons (and uniforms and people etc.)
To quote Rhett Butler: "All we [the South] have are slaves and arrogance"
And the good folk of Washington, DC thought that it would be brief. Hell, they went out on picnics to watch the first engagement.
Again, those who think civil wars are brief and victorious are invited to go see one up close.
And it still took four long, hard, bloody years. A few rolls of the dice resulting in different "alternatives" .. or General Jackson not being stupid enough in riding outside his lines in the dark at Chancellorsville .. and your "brief and bloodless" Civil War would have ended after only maybe two years.