Today remarkably across German-speaking countries Switzerland keeps a very high level of usage of dialects other than Standard High German (SHG). Although non SHG-dialects are also commonplace in Austria, it's not on the same level of Switzerland, where Swiss-German appears in everyday life in every situation.
Up to mid 19th Century this was also the case across most of the German Sprachraum, although a standardization trend started to appear back then.
One of the reasons commonly cited for Switzerland keeping it's dialects is the "Defensive spirit" of Switzerland during WWII where the Swiss sought to show a different national identity from that of it's neighbors, with increased use of Swiss German, institution of Romansh as a national language, etc.
What I can't find are sources, or data or any sort of information regarding the use of Standard High German in Switzerland between the mid-19th Century and WWII. I'd assume the same pattern of standardization was happening in the country, which was reversed on WWII and kept like this ever since, but I have no sources to check that.
Are there information, sources, etc regarding the usage of Standard High German/Swiss German in everyday life in Switzerland before the rise of Nazism in Germany?