How does Tony Horwitz use imagery in Confederates in the Attic: Dispatches from the Unfinished Civil War?

Examples of Imagery:

"Hodge looked as though he'd stepped from a Civil War tintype: tall, rail thin, with a long pointed beard and a butternut uniform so frayed and filthy that it clung to his lank frame like rages to a scarecrow."
Chap. 1, p. 7

"The day before the Wilderness battle, Rob dropped by to lend me some gear: foul-smelling socks that might once have been white but were now splotched amber, a butternut 'trans-Mississippi officer's shell jacket,' gray 'JT Moore' trousers, a 'smooth-side 1858 model' canteen, and a 'tarred federal haversack.' None of this meant anything to me, but I was given to understand that I'd resemble a walking museum piece."
Chap. 6, p. 127