Transportation and technology 19 century

The 14th amendment overruled the supreme court case of dred scott vs. sandford. the landmark supreme court case determined which of the following points? a.slaves could not be citizens b.non-landowners could not be citizens c.blacks could not be citizens d.all persons born or naturalized in the united states vary differently in citizen status.

How do you think entrepreneurs contribute or industry in america? describe your answer.

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.