The section on the Rise of the Nation State has a quote at the end of the video lesson (which covered the 1850s-1870s) that stated "Nationalism and Unification in Europe would have huge effects, especially in the next 75 years."
In what ways did the events of the 1850s-1870s have huge effects, especially in the next 75 years? What are examples of
events of the 20th century (1900s) that were influenced from Nationalism and Unification?

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.