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American Civil War; specifically the battles of Antietam, Fredericksburg, Gettysburg, and Civil War Actions in and around the Maryland area. Civil War period Medical questions (types of surgery, medications, treatment of soldiers and civilians)
Written three battlefield guides for the battles of Antietam, Fredericksburg, and Manassas for the US Marine Corps, including taking Marine officers on guided tours of same. Currently a Medical reenactor with the "Stonewall Brigade" and serve as their "Brigade Surgeon". Live in the same area that I have experience in, grew up "walking the fields".
27th Virginia Infantry (Reenacting Group)
Society of Civil War Surgeons
Authored 3 Battlefield Guides for Fredericksburg, Antietam, 1st Manassas. These are currently in the US Marine Corps Warfighting lab at Quantico, Virginia.
Long study of the Official Records of the War of the Rebellion (have on CD Rom), as well as reading the stories of the soldiers (and Surgeons) "on the field" for the sheer enjoyment of it.