Not much info at all on Solomon Pettibone. He is only mentioned in passing. But the link contains a fascinating victim account of the 1862 Minnesota Sioux Uprising.
That Indian war resulted in many deaths and culminated with the trial of 395 Sioux Indians for the murder of 480 white settlers (including women and children). Death sentences were given to 303 of the Indians and on 26 December 1862, 38 of them were hanged simultaneously on the same gallows in Mankato, Minnesota. President Lincoln commuted the death sentences of the others.