ACT OF MEDIATION
February 19, 1803

The Act of Mediation, or in German Vermittlungs-Akte, was thought up by Napoleon and added the following six Cantons to Switzerland: Sankt Gallen, Graubünden, Thurgau, Tessin, Aargau, and Vaud.

The Mediation Act was abolished December 23, 1813.

And here is the map

1803 Switzerland