What led to the development of one-crop economies?

Before the civil war, the south’s economy was based on enslaved labor. large cities. immigrant workers. factories.

Why did anne frank feel that the germans were the enemy?

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.