After checking out the sources it appears to me that Stef was slightly mistaken in regards to the Santee Sioux massacre. From what I understood, Stef said that Lincoln had 300 natives executed but lied about the numbers because he feared losing support across the Atlantic. All sources I checked (including the ones linked in the video) uphold that Lincoln did in fact narrow it down to 38 that were actually executed while most of the others were pardoned or died in prison. Obviously still a grotesque and significant massacre, but I thought this distinction was worth noting since after all we are in pursuit of the truth!