[masklinn]

Also "the language"? The french republic started actively suppressing all local languages (breton, auvergnat, arabic, kabyle, …) starting from the mid 19th century and until late in the 20th, this ramped up significantly with the free, universal and mandatory education laws of 1881 and 1882: all education was done in french.

Alsatian is probably one of the local languages which suffered least due to Alsace having been conquered by Germany in 1870, and being reintegrated with its own set of laws and exemptions in 1918.

Hell, the republic just grouped everything which wasn't standard french under patois, regardless of them being languages, dialects, creoles, ….

Though just so we're clear, this is a long-standing issue of the french state and its centralised habits: Louis XIV banned Catalan back in 1700.