Well now... does that include Africa? Or the totally-uncolonised Wild West?

Heck, in Europe river transport continued to be strongly developed all throughout the century, especially where given nations couldn't afford a strong rail network. So, for example, the Vistula was by far the main export route from Russia-controlled Poland. But even in more developed areas, the same thing happened - the Germans built up a very strong river barge fleet on the Oder, because it was just so much cheaper to send coal down the river on a barge than ship it via rail. This wasn't the case in the UK, because it lacks rivers of significant length, so trying to make use of river currents is not in the least economical.
It would be pretty nifty if a basic canal network and/or road network was a buildable option. Yes, virtually every provice in Europe would start off with this in place - but it would give the US and the Uncivs something to do in the early game. Options like this would allow the removal of the blunt "uncivs get 10% of the province income that a civ would get" system - instead, the uncivs' lower income would be justified by the absence of these improvements, and the player could actually have a (shock, horror) fun time leading some obscure uncivilised nation to industrialisation.
I would suggest two things - first up, a river (and coast) infrastructure thingy that has a few levels of infrastructure (eg., 1 - natural rivers/coastlines, 2 - regulated rivers, 3 - canal network, 4 - steam paddleboat network, and 5 - steamboat network), and a buildable stagecoach road network as the first level of the railroad infrastructure.
The fun thing about having a separate river infrastructure is that it would help drive colonisation in Africa and the US along rivers - the Missouri and the Congo, for example. Provinces that lack navigable rivers would not be able to build up this kind of infrastructure, and so would have a lower accessibility/life rating for colonists. Might help with the US Civil War, too - wasn't there a whole lot of fighting in the Mississippi Valley, which would have been entirely pointless in Victoria's riverless context?