What was the result of the supreme court ruling in gibbons v. ogden

What might balance federal and state powers present a problem

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.

Which of the following was the largest group of people living in the region of transylvania? a. german b.slavic groups c.romanians d.italians