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https://www.britannica.com/biography/Frederick-Jackson-Turner

https://www.usmcu.edu/Portals/218/Turner%20Thesis%2C%20Frederick%20Jackson%20Turner.pdf

https://en.wikipedia.org/wiki/The_Significance_of_the_Frontier_in_American_History

https://keywords.nyupress.org/american-cultural-studies/essay/west/#:~:text=Making%20explicit%20the%20ideological%20links,US%20national%20and%20imperial%20designs. 

https://en.wikipedia.org/wiki/Frederick_Jackson_Turner

https://en.wikipedia.org/wiki/Richard_Slotkin

https://www.britannica.com/biography/John-C-Calhoun 

https://en.wikipedia.org/wiki/Missouri_Compromise 

https://en.wikipedia.org/wiki/Hermann_Eduard_von_Holst

https://en.wikipedia.org/wiki/Knights_of_the_Golden_Horseshoe_Expedition 

https://en.wikipedia.org/wiki/Alexander_Spotswood 

https://en.wikipedia.org/wiki/George_III 

https://en.wikipedia.org/wiki/Royal_Proclamation_of_1763 

https://en.wikipedia.org/wiki/1790_United_States_census 

https://en.wikipedia.org/wiki/1820_United_States_census 

https://www.britannica.com/money/American-Fur-Company 

https://en.wikipedia.org/wiki/Francis_Grund 

https://en.wikipedia.org/wiki/Allegheny_Mountains 

https://en.wikipedia.org/wiki/American_Indian_Wars 

https://en.wikipedia.org/wiki/First_transcontinental_railroad 

https://en.wikipedia.org/wiki/Territorial_evolution_of_the_United_States 

https://en.wikipedia.org/wiki/Achille_Loria#:~:text=Achille%20Loria%20(2%20March%201857,was%20an%20Italian%20political%20economist.&text=He%20was%20educated%20at%20the,University%20of%20Bologna%20(1877) 

https://en.wikipedia.org/wiki/Cumberland_Gap 

https://en.wikipedia.org/wiki/South_Pass_(Wyoming) 

https://en.wikipedia.org/wiki/Ren%C3%A9-Robert_Cavelier,_Sieur_de_La_Salle 

https://en.wikipedia.org/wiki/Michel-Ange_Duquesne_de_Menneville

https://en.wikipedia.org/wiki/Albany_Congress 

https://en.wikipedia.org/wiki/War_of_1812 

https://en.wikipedia.org/wiki/Cattle_drives_in_the_United_States 

https://en.wikipedia.org/wiki/Lewis_and_Clark_Expedition 

https://en.wikipedia.org/wiki/Kanawha_saltworks 

https://de.wikipedia.org/wiki/Victor_Hehn 

https://en.wikipedia.org/wiki/August_Gottlieb_Spangenberg 

https://en.wikipedia.org/wiki/Daniel_Webster 

https://en.wikipedia.org/wiki/Daniel_Boone 

https://en.wikipedia.org/wiki/Kit_Carson 

https://en.wikipedia.org/wiki/John_Mason_Peck 

https://en.wikipedia.org/wiki/1890_United_States_census 

https://en.wikipedia.org/wiki/Melting_pot 

https://en.wikipedia.org/wiki/Edmund_Burke 

https://en.wikipedia.org/wiki/Joseph_Campbell 

https://en.wikipedia.org/wiki/Howard_Mumford_Jones 

https://en.wikipedia.org/wiki/Kenneth_Rexroth 

https://en.wikipedia.org/wiki/Robert_Frost 

https://en.wikipedia.org/wiki/Cotton_Mather 

https://en.wikipedia.org/wiki/Roger_Williams 

https://en.wikipedia.org/wiki/John_Underhill_(captain) 

https://en.wikipedia.org/wiki/John_Filson