CONFIRMEDDate confidence: CONFIRMEDStated as firmHow firmly the source words the date: confirmed, scheduled, estimated, delayed or unverified.Show all CONFIRMED pins85% CONFIDENCEOverall confidence: 85%How well the pin's source and references back up its dates.Weighted average of how firmly 3 references, the source included, support the pin's start and end times; a reference counts half as much for every 180 days older than the newestShow all pins at 75% confidence or better126.3 years ago
RATP's[3] own history page gives 19 July 1900 as the inauguration date of the first métro line; EarthSky's[2] science-history article gives June 19, 1900, a month early.The Paris Métro's first line opened to the public on 19 July 1900, running between Porte Maillot and Porte de Vincennes.