According to Airlines of the United States (AKA bible) by R.E.G. Davies (aka God), the first scheduled passenger air service in the US was the St Petersburg-Tampa Airboat Line which operated flights between Tampa and St Petersburg. The flights were operated under contract with the City of St Petersburg between Jan 1, 1914 and March 31st 1914. OK well it was not year round service, but it was still the first and it was before those french flights.
According to Mr Davies book, the Ryan flights between San Diego and Los Angeles was "the first regular passenger airline service to be wholly operated over the mainland of the United States, throughout the year". Boy is that a mouthfull.
Pacific Marine Airways had been operating from Wilmington CA to Catalina Island since 1922 but during some times of the year, flights were operated on an on-demand basis.