Martin Luther King ,Question’s 2&4 ,will give brainliest if both answered and explained.

How were returning african-american soldiers treated in american cities in 1919–1920?

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.

Describe the views of the federalists. how did they feel about ratifying the constitution.