Ken,

The story of the flag capture comes from a letter written in May 1862 to his half-sister (Lydia Ann Reed) that can be found in the Monroe (MI) County Library. The letter was cited in both Jeff Wert's and Greg Urwin's Custer books as well as an older one written by Merington (which I do not have). Wert incorrectly IDs this flag as that of the 5th NC by the way. Custer wrote:

"The battle of Williamsburg was hard fought, far more so than Bull Run. I captured a Captain and five men without any assistance, and a large rebel flag."

Winfield Scott Hancock's OR report (OR I, Vol. 11, pgs. 533-543) mentions Cuter three times, twice for merit in a list of others of his command who performed well. Custer was a staff officer for Hancock in this battle.

In one part of the report, Hancock writes that Custer lead an attack on his horse of the 5th Wisconsin and 6th Maine on Fort Magruder. This fort was found unoccupied and this may be where Custer got the flag. The Confederates were beyond this fort where the 5th NC and 24th VA engaged Hancock's Brigade. I do not know what CS unit held Fort Magruder before it was abandoned. If this was where the flag was found then it was one of the VA units - 24h or 38th VA.

With regards to Custer taking the flag in battle and then dashing back to his lines with it as a possible capture mode, Hancock's report also mentions a sergeant of the 33rd New York who, with 8 men, was cutoff from their own skirmish line but managed to breakout and return to their lines capturing 42 prisoners including a captain of the 5th NC. (Page 542).

There is also one account in one of the Medal of Honor books about a Union soldier doing something similar in taking a CS flag - dashing to the fore, getting the flag and returning with it safely. I will have to flip through the two books I have on CW MOHs to see who this was but I read it in one of them some time ago. So anything in combat is possible.

Greg Biggs