The largest single execution in United States history was the hanging of 38 American Indians convicted of murder and rape during the Dakota War of 1862. They were executed simultaneously on December 26, 1862, in Mankato, Minnesota. A single blow from an axe cut the rope that held the large four-sided platform, and the prisoners (except for one whose rope had broken and who had to be re-hanged) fell to their deaths. The second-largest mass execution was also a hanging: the execution of 13 African-American soldiers for taking part in the Houston Riot of 1917. The largest non-military mass execution occurred in one of the original thirteen colonies in 1723, when 26 convicted pirates were hanged in Newport, Rhode Island by order of the Admiralty Court.

How many people were killed in the largest mass execution in US history?