Now, what would make those people hostile? 
It is bad enough U.S. history books are filled with derogatory references to Natives as - Indians, redskins, injuns, heathens, savages, pagans, and barbarians. Even our Declaration of Independence refers to them as "merciless indian savages." But to be baffled by their hostility? It never seems to occur to those troopers that the Natives are hostile precisely because those troopers are invading their land, taking their food, and killing their family members. If Natives regularly pushed their way into the various forts the US military had established along what was called the frontier and were taking off with all the goods they could carry, how would the troopers react? Would they be hostile toward people who did that to them? Why were the people who already lived on that land considered the invading culture? Why were they required to give up their land just because white intruders under their self-appointed Manifest Destiny decided they owned whatever they could see or grab? In the United States, white trespassers still occupy Native lands.
"Where did they come from?"
For example, here is the most likely scenario that happened along the coastal area of what became Virginia on May 13, 1607, when a Powhatan native came across the first English invaders. In basic sign language, this occurred:
Native: Who are you?
Immigrant: We're here to build a settlement named after our king, called Jamestown, on this land.
Native: Why?
Immigrant: Is this your land?
Native: Yes, we hunt and fish here. Who is your, uh, king to give you this permission?
Immigrant: We're here on his orders. See, here is the signature of King James.
Native: Is he with you?
Immigrant: No. But his name is on this piece of paper, making it legal.
Native: So, you're guided only by marks on a piece of what looks like thin skin of some sort. The man who made them is not with you. There seems to be just a small group of you with no females, and many are doing nothing...
Immigrant: Most of us are sick.
Native (looking around): Unaccompanied, seems to be a minor bunch who are in poor health. To do anything else would be inhumane...so, alright, you can stay here for a while. We'll send over some food. The water in that river is no good...too salty. There is a spring not far that way with good water. The trees provide plenty of cover for protection - and for heat and cooking. We'll check up on you.
Immigrant: We can never repay you.
And they never did. As a matter of fact, they took it away from the natives.
The same scenario played out on November 11, 1620 (per the Julian Calendar), near what became Plymouth Rock in Massachusetts. There, the circumstances were even more problematic and dire for the Pilgrims. (They had put the 'grim' in their religious identification due to their own intolerance for other viewpoints, which is why they were now seeking a new homeland.) Winds had blown them off course, so they did not get to where they were attempting to reach in the "New World." Now, it was almost winter, and they had used up most of their supplies to get to this uncharted place. The Wampanoags were the only reason the Pilgrims survived the first winter. The Pilgrims had tried to pray their food, safety, care, and well-being into existence. But, whatever they were praying to took no note of them. The Natives took pity on the strange invaders and extended to them far more "Christianity" and Christian character than the Pilgrims ever reciprocated.
"Our king and our church said we own you people now...and your land, too!"
Meanwhile, down in the territory being vandalized by the ever-so-compassionate conquistadors of Spain, St. Augustine had been established in 1565 as a Catholic mission. It was a foothold for the Spanish conquest of the territory. To really get things off on the wrong foot, since 1513, there had been lots of barbaric treatment of - and violent contact with - the local natives, like the Timucuans and the Calusas, as the conquistadors fought their way into this new land. This would foment an even more hostile living environment that would be the future of interaction between the two cultures in what became Florida.
The conquistadors had the noxious habit of enslaving any person who fell into their hands because the church ruled that they could. The people they met were heathens. They were not to be afforded God's mercy and treated as equals. They were sub-humans in the eyes of the church because they didn't worship the same god, they spoke a weird language, and they had different customs. How dare they?
The Spaniards abused them in every way they could: they used them as targets, to ride on like animals, and forced at swordpoint to mine metals or ores out of the ground, or plant and farm crops. The Natives were not malleable at all and resisted every effort of the Spaniards to subjugate them. All that was left was to kill the indigenous men and rape their women. That would spread their "friendly-to-whites-only" diseases throughout the local population, and then they'd just wait for nature to take its course. The same callous attitude was displayed toward the indigenous by the English, French, Dutch, and Portuguese as well.
Naturally, they couldn't have known that the diseases they carried, that they were immune to from centuries of living in Europe, these people had no defenses against. Even a simple cold was lethal to many of the indigenous. But the invaders didn't know, nor did they care. They assumed the Indigenous land was theirs for the taking, so if the inhabitants got the sniffles and died, then the white invaders could justify it by saying, "It was an act of God and was meant to be!" 
That is what made the butchery, cruelty, and hostility so disturbing: the cold-blooded treatment of all Natives by these invaders based solely on their holy book, the Bible, which they all claimed guided them. Since these indigenous people were different in enough ways, the invaders asserted that their God's attitude was "do whatever you want to them." Such Christian compassion and charity!
Enslavement was condoned. Barbarity was approved of. Seizing land without verifying if anyone lived there first was seen as a noble thing to do for their king and god. It spread their gospel...while spilling blood everywhere it was carried and preached. It didn't matter that the natives couldn't understand a word of what the Spaniards were babbling at them. The church leaders had told them all should hear the word of God. That meant the monks and priests with them read it out of their books - because of course God would intercede and make the natives understand Latin in their own language - so they had to stay and be quiet, then profess to grasp and accept whatever was shouted at them. When that failed over and over and over, the church ordered them slaughtered. Better no heathens at all, especially those who heard the word and rejected it. This scenario was played out everywhere these European Christian-influenced invaders set foot...the Caribbean Islands, Mexico, Brazil, Australia, New Zealand, Africa, India, Singapore, China, Hawaii...etc. In a little over 100 years, North, Central, and South America became the testing ground for all the appalling and criminal actions these invaders could think up in dealing with a new race of people. If it was the wrong thing to do, these invaders did it.
The Tainos couldn't understand why the Columbus crew needed so much material draped over them.
When Columbus and his followers stumbled upon the Caribbean Islands and the Americas, he and the Spanish hooligans who came after him instituted a bloody legacy reputedly established much earlier by the Vikings. In those Norse legends, Leif Ericssen and Eric the Red fought men called skraelings in their encounters far to the west of their Northern European homelands. Not to be outdone, the conquistadors came up with a variety of ways to terrorize anyone they encountered that would humble whatever violence the Vikings unleashed.
The British, French, Dutch, and Portuguese enhanced that blood-thirsty reputation when they got to the New World. In many cases, they were almost giddy about their barbaric treatment whenever they came in contact with the indigenous people.
And then, on top of all that, the hypocritical Americans insisted on calling the native people they encountered while pushing westward into their lands...savages!
And yet some people don't think any reparations are owed to the indigenous people, to those who are descendants of the African Slave Trade, and to the descendants of the Asian 'Coolie' Trade. How in the hell can any person look at the information that is currently available - information that white people recorded without any embarrassment - and not think these abused people are due SOMETHING for all they have suffered and been subjected to at the hands of our Caucasian ancestors? To deny them that is a strikingly undiluted example of white privilege.
The people who endured the barbarism of that white privilege deserve justice. It is long, long overdue.
