Statistics for occurrence #1 of “General Sedgwick” in chapter 9, page 89 of Isaac O. Best, History of the 121st New York State Infantry:
...gan the pursuit, the First Division having the lead, marching by the Fairfield road.
The rear guard of the enemy was soon encountered and brisk skirmishing ensued, but no general attack was made.
General Sedgwick decided to attempt to cut off the crossing of the Potomac by the enemy, by a flank movement over South Mountain and led the Corps by a steep and rugged pass
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