Also people forget that up to the 1830s, going from Paris to Marseille was a 2 week journey (unless you were a royal courier switching horses every 40 km, who could do it in a few days), and that sending a message across the Atlantic and getting a reply a 2 month affair. In the late 1860, going from Paris to Marseille was done in about 15 hours by train; it only got gradually faster since then (nowadays, 3h30, by train or by plane).