Re:Small Orbital Device Kills Everyone (Score 1)

Species migrating is natural. Viruses, bacteria, and other diseases are natural. Unless the OP is suggesting we held the Indians down and injected them with smallpox, the analogy holds.

Well they didn't injected it, but close. It also seems the British were responsible and not the U.S. From wikipedia:

Smallpox was probably first used as a biological weapon during the French and Indian Wars of 1754-1767 when British forces in North America distributed blankets that had been used by smallpox patients among them to Native Americans collaborating with the French.

This was only a single instance though. Most Native American deaths due to smallpox seem to have been unintentional.

This method also wasn't as rare as the OP seems to think. Catapulting the bodies of plague victims over the city walls during a siege was a known tactic during the middle ages.