First NC Cavalry Strength
John Owen Allen, "The Strength of the Union and Confederate Forces at Second
Manassas," Masters thesis, George Mason University, 1993, shows 411 in 10
companies on 2 September.
The number from Meier's Antietam PC game: 237.
My guess is that probably about 300-350 crossed the Potomac into Maryland.
Maybe 237 is a good guess for 17 September.
Do you have numbers from other sources?