How did henry clay propose to admit california to the union without upsetting the balance between slave states and free states?

Approximately how many americans, from both the north and the south, were killed in battle during the civil war?

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.

What are some effects outside of europe because of world war 1?