David,
It probably was the "Frank James". Problem the Younger and James boys had was when they expanded their operation to Northfield, MN.
They were used to the gentle folks of Missouri and Kansas.
Those Norwegaians, and Swede's and Finns of the North country never heard of the bad James gang. All they knew was that no one was going to take Olie and Svens money. So they unlimbered their '66 and '73 Winchesters and the trusty old 12 guages and gave them a fit.
Frank