The Largest Mass Execution in US History
On December 26, 1862, following the U.S.-Dakota War of 1862, the federal government hanged 38 members of the Dakota tribe in Minnesota. It was the largest mass execution in United States history.
Two days after the Dakota surrendered at Camp Release on September 26, 1862, a military commission began trying Dakota men accused of participating in the war. The rapid trialssome no more than five minutesof 392 prisoners were completed in November. According to the Minnesota Historical Society, 303 men were sentenced to death and 16 received prison terms.
After reviewing the trial transcripts, President Abraham Lincoln provided a list of 39 names of prisoners to be executed. One received a last minute reprieve. On the morning of December 26, 1862, in front of an estimated crowd of 4,000 spectators and on a specially constructed mass-hanging scaffold, the men were executed. They were left dangling from the scaffold for a half hour.
https://deathpenaltyinfo.org/stories/the-largest-mass-execution-in-us-history