You have turned the facts upside down. You're quoting Heather Cox Richardson, one of the most biased and misleading scholars on the Wounded Knee incident. Wounded Knee was a battle started by some fanatical Indians who were brainwashed with the Ghost Dance myths. The Indians fired first. Many of the soldiers held their fire to avoid hitting women and children. Most of the women and children who were killed in the initial fighting were killed by their fellow Indians. Have you heard of Father Francis Craft? He was an "Indian lover" who witnessed the event, and he said that the Indians fired first and that all the soldiers he saw fought honorably.
Here's my main article on Wounded Knee:
Unwanted Facts about Wounded Knee.
Here's a shorter, introductory article on Wounded Knee:
Getting Some Basic Facts Straight About Wounded Knee.
Here's my website on the battle:
Wounded Knee: A Battle, Not a Massacre.