President Lincoln authorized the largest mass execution in US history of 38 Dakota Indians in 1862 over the Dakota Conflict. Lincoln actually commuted most of these sentences, as the number started off at 303:
The final decision on whether to go ahead with the planned mass execution of the 303 Dakota and mixed-bloods rested with President Lincoln. General John Pope campaigned by telegraph for the speedy execution of all the condemned. Virtually all of the editorial writers, politicians, and citizens of Minnesota agreed with Pope. One of the few who did not was Henry Whipple, the Episcopal bishop of Minnesota. Whipple traveled to Washington to meet with Lincoln and discuss the causes of the Dakota Conflict. Lincoln later wrote of Whipple's visit, "He came here the other day and talked with me about the rascality of this Indian business until I felt it down to my boots. If we get through this war, and I live, this Indian system shall be reformed!"