What are two groups who discovered america by crossing the atlantic before columbus? (not the vikings)

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.

Explain the importance of carnegie, morgan, and rockefeller on the american political scene of the early 1900's.

Analyze the quotation below in the context of european exploration in the americas. as you read the quote, think about what it says about columbus's motivations to explore. was he interested in gaining knowledge, wealth, or both? how did his motivations influence how he treated the people already living in the americas? i did not try to examine them in detail, because it could not be done in 50 years. for my desire is to see and discover as much as i can before returning to your highnesses, our lord willing, in april. it is true that in the event of finding places where there is gold or spices in quantity i should stop until i had collected as much as i could. i, therefore, proceed in the hope of coming across such places.