The initiation of European invasion into the Americas caused a drastic shift in how European nations undertook colonization and conquest. While these activities were very much a European priority prior to the Conquistadors, they took a different form in the Americas—eventually resulting in new cultures and attitudes regarding the concept of nationality.
Because it took an incredibly long time for solid, permanent settlements of Europeans to be established in the Americas, resource extraction was undertaken through slavery. First this was achieved through the Encomienda system, in which Spanish invaders demanded tribute from designated communities of Native people under penalty of torture and execution. This system failed fairly quickly, however, because of how it decimated Native populations; eventually, there weren't enough bodies to be broken in the name of fulfilling European greed. European conquerors then turned to importing enslaved people from Africa, creating what became the transatlantic slave trade.
While slavery had existed in Europe for centuries before New World colonization, this was the first time people were brought so incredibly far from their homeland and in such great numbers to be worked. As generations have passed, this displacement, combined with the emigration of white settlers, has shifted and created new cultures and senses of nationality: there now exist both white American and African American cultures and subcultures, and many people now consider their nationality to be different from their race or ethnicity.
In my own opinion, I think it is impossible to separate any cultural effects of this displacement from the horrors of the thing itself. I have found every argument I've heard that slavery and genocide could possibly benefit anyone to be entirely grotesque, because I cannot fathom how anything could justify such human suffering. However, it should be noted that I am white, and so my opinions on the experiences of Black people do not come from any personal experience of racism and are thus limited in scope and relevancy.