Marcy,
I seem to recall that in 1862 Quantrill and his band raided someplace on the MO/KS border and an old pen-and-ink drawing shows his band hung several northern sympathizers in trees. This new location of inside or near Leavenworth County SEEMS to fit your other clues better than the Osage County story. I cannot offhand recall if this 1862 mass hanging was in Kansas or Missouri. We are in the process of moving, and my resources are in the other house. I'll be going there toward the end of the week to accept a shipment, so this will have to wait a few days.

This new circumstance of the death of Walland in or near Leavenworth County (with 11 other guys) rather meets the age of his young son, too. There was also a mass hanging of 16 men at the center of MO, but it does not fit your other clues of Jefferson Township, SE Osage County, and the age of Walland's son. To be blunt, the earlier clues you gave me don't fit any mass hanging stories I read, but this new clue from "The Best of Basehor" SEEMS to fit one story I have. Your ancestor search is back on the rails, but we have to check out the details to see if they fit the Quantrill story.

Until later, Bruce