To Phil Oliver's list of resources I would add "Gettysburg - The First Day" by Harry W. Pfanz. The David Martin book is excellent, the Pfanz one is in my opinion better.

Also, the "Gettysburg" magazine article by the Storches is entitled "What a deadly trap we were in" and was in issue #6 of the magazine, Jan 1992. An excellent piece, exhaustively referenced.

I have found it difficult to place the regiment-by-regiment movements of Archer's Brigade during the Willoughby Run action. Authors don't even agree on the ordering of the regiments in the initial battle line, N to S. However, it seems to me that the 1st TN was in the thick of things where Archer was captured, and it was the 1st TN sharpshooters that were out front with the skirmishers (when Reynolds was killed??).

Cheers,
Woody