Reddit reviews The Last Full Measure: The Life and Death of the First Minnesota Volunteers

1st Minnesota. https://www.amazon.com/Last-Full-Measure-Minnesota-Volunteers/dp/0873514068, Here's a decent book on them.
They were solid soldiers, who did their job, however like most regimental histories it sort of stretches their accomplishments.
At Gettysburg their stand was against Part of Wilcox's Alabama Brigade, (2 regiments the 10th and 11th) Wilcox's men had already broken through two lines of Infantry and captured a battery 8 pieces of Artillery. The 1st was credited with supposedly facing Wilcox's entire brigade of 5 regiments ... hence the 5-1 odds often quoted.
Wilcox's after action report mentions over-running a union position near cemetery ridge than having to fall back because no support was nearby, having to abandon the 8 guns they captured.
Even if the 1st Minnesota hadn't been set forward two depleted Regiments could never have held the position.
During the 3rd ( Pickett's Charge) the remnants of the 1st Minn were in reserve. They went forward pretty much after the issue was settled and Private Marshall Sherman picked up the fallen colors of the 28th Va and received the Medal of Honor.
One thing not in Dispute is that the 1st Minnesota had the highest single percentage of men killed and wounded in a single battle, 82%. What was left of the 1st Minnesota were discharged in April of 1864 when their enlistments ran out, with a year of fighting left.
Some of the men reenlisted and were the basis for the 1st Minn Battalion which served until the end of the war.