Answer:
the transcontinental railroads were built all around the US and were used for trade and to transport goods all over the place
The Congressional power is known as the Supremacy clause.
In Article 6 Clause 2 of the United States Constitution, it states that federal laws are the supreme laws of the land. This means federal laws trump all other laws in the United States. So if the federal government wants to prosecute people for the possession of marijuana in a state where it is legal, they can legally do so thanks to the supremacy clause.
Seems that you may need to provide your own information that you’ve gained! you haven’t included the crash course video. i would recommend watching the video over and picking out 3 things that you learned. i’ve seen crash course videos before (not the one above of course) and they’re very easy to understand and there’s TONS of info, it’s quite easy to pick out three things :)