1848 saw rising political tensions in Paris, which overthrew the monarchy in February and culminated in the June Days uprising, when Meryon's immediate neighbourhood saw some intense fighting around the barricades thrown up by the insurgents. He was a member of the National Guard (probably obligatory for a naval officer on leave), which played a crucial role in resisting the uprising on behalf of the French Second Republic, which Meryon generally supported. He "spent almost three days in the street, broken only by hours snatched for sleep", and was slightly wounded.