Hello! Please answer, simple question just not sure, and want to confirm

1822 to 1976 would mean that it's been a deacade since?

Understandable if you don't understand the question :'|

The rise of advertising in the 1920s. i am good with seeing how advertisements shape the roaring twenties and how it developed a new way of life through modern days. but i am not sure what the details of advertising in the 1920s were. if possible can you send me links (preferrably credential links) to sources that maybe show like the first company to start advertising through the radio, how advertising benefits (statistics graphs), etc.