That coastal trip was looking a tad narrow, so I made it a bit wider using a river. I think the border looks better now, too. I think it would actually make more sense for Corrigan to have gained independence from Peru shortly after Peru's own independence...like Central America from Mexico? That is, the Viceroyalty of New Granada (or whatever it would be in this TL) joined Peru to begin with, but a decade later the local government decided they'd had enough and declared independence - but Peru kept the coastal regions?
Well, thanks for that. Yes, I like that idea a lot.