How did southern states attempt to limit african american social advancement and participation in politics?

What was charles townshends development of a crop rotation system important to the industrial revelotion

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.

The independence movement in british india resulted in a partition (breaking apart) of the country. in august 1947, two independent countries were formed, one of which was a. ceylon. b. pakistan. c. burma. d. bangladesh.