[Nomentatus]

The US is large, true. More a matter of control points, such as Harper's Ferry. That's where Lee had to punch through to get to Antietam, in 1862, for example. https://www.nps.gov/hafe/learn/historyculture/1862-battle-of...

But I haven't asserted that all regular wars have front lines all the time. Just that guerrilla wars don't.

[philwelch]

I don’t think this phenomenon is specific to the US, but to the era. I’m just not quite as familiar with e.g. the Napoleonic Wars.