He was a railroad baron from Minnesota who built railroads connecting Minnesota to Washington state.

d. dr. francis collins

explanation:

i think it is in quadrant 4.

the five year plans were part of a command economy. there was little choice in what would be emphasized for the current 5 year period.

the answer to democracy or totalitarianism is a bit harder. in stalin's time, russia was totalitarian. now that's not entirely true. putin has moved towards at least the boundary.

a system of cooperative federalism emerged, as the powers of the federal government expanded.

i believe it would influence their own way of understanding things. it shall be a foundation where they can draw or start an argument.   historians are also  scientists that  have their tools of analysis and expertise to unlock a variety of difficulties such as relationships of man, origin, politics, economy, and culture. based on facts and understanding on these areas, they may shade light to extract ideas and develop options to validate a hypothesis or debunk it.