December 26 marks the 150th anniversary of the largest mass execution in American history…the hanging of 38 Dakota Sioux Indians in Mankato, Minn., which marked the end of the Dakota War of 1862, also known as the Sioux Uprising.

A new monument to those hanged, replacing one dating back decades, was dedicated this morning in Reconciliation Park in Mankato, the location where the executions are believed to have taken place.

The 2-hour ceremony drew a crowd estimated at around 500 people, including a group of Dakota runners from Fort Snelling and about 60 horse riders…most of whom arrived in Mankato earlier after a 2-week ride from South Dakota.

Mankato resident Bud Lawrence helped start the reconciliation effort in the 1970s, and called the rededication “a great day, not only for the Dakota but for the city of Mankato.”

The Santee Sioux tribe in northeast Nebraska has remembered the executions for several years with a ceremony that this year included a number of horses dressed in Native American regalia with drapes commemorating each of the men killed.

Santee Tribal Council chairman Roger Trudell says the executions are a piece of the nation’s past that not many people know, but that are important to the Santee because nearly all the members of the tribe are direct descendants of those killed in the hangings.

The Sioux Uprising began on August 17, 1862, when one young Dakota in a hunting party of 4 killed 5 settlers. That night a council of Dakota decided to attack settlements throughout the Minnesota River valley to try to drive whites out of the area.

Battles continued for several months, but as more troops were brought in despite the Civil War, most of the Dakota bands had been captured by late December. There has never been an official report on the number of settlers killed, but it’s put as high as 800.

In early December 1862, 303 Sioux prisoners were convicted of murder and rape by military tribunals and sentenced to death while Minnesota Governor Alexander Ramsey called for the extermination of the Sioux Indians of Minnesota.

President Abraham Lincoln personally reviewed the trial records to distinguish between those who had engaged in warfare against the U.S., versus those who had committed crimes of rape and murder against civilians.

In the end, Lincoln commuted the death sentences of 264 prisoners, but allowed the execution of 39 men…one of whom was granted a reprieve before the rest were hanged.