Which event is most likely to occur in a tragedy?

Why did jefferson make the louisiana purchase?

•the impact of enlightenment ideals on the development of economic, political, and religious structures in the western world

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.