The growth of national railroads in the late 1800s had what major effect on the united states

Based on source 1 which political strategy did sncc most likely support to bring about change in society?

What event from world war l does the image most likely depict

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.