There are claims being made in the Scottish press this week that The Glasgow Looking Glass, published in the mid-1820s, was the world's first comic. Unfortunately it's hard to tell for yourself, because the examples shown in the online newspaper stories are all isolated panels, and if you have read your Scott McCloud you know that the essential property of a comic is sequentiality. To be a comic a cartoon has to have at least two adjacent panels that are in some kind of linear narrative relationship.
But view the video in the Sky News site. You can see that while most of the panels are isolated single-panel cartoons, some of them work together by contrasting before and after or them and us. That would be enough lift them from the category of political cartoon (which was well-established by the time of the Napoleonic Wars) into the realm of comics, if accidentally.