His nickname is probably the meanest one of the bunch—when you call somebody a coot, it's actually a way of referring to them as a pest (it's an old slang term for lice). Still, Coot's story definitely packs a wallop when he gets to talking. Then again, when Coot shows up wearing his old World War I army uniform—even if it is old and full of holes—when other folks are wearing their usual stuff, Gaines is letting us know that things are a little different with old Coot.
But don't take our word for it. Think about what he says. He enlists and goes off to fight the Germans in the war, and gets put in a segregated all Black regiment. He and his pals fought hard. They got medals, were recognized for their valor, and were proud—especially Coot:
I was proud as I could be, till I got back home. The first white man I met, the very first one […] told me I better not wear that uniform or that medal again no matter how long I lived. He told me I was back home now, and they didn't cotton to no n***** wearing medals for killing white folks. That was back in World War One. And they ain't changed yet—not a bit. Look what happened to Curt's boy when he come home from World War Two. (9.189)
Coot lets us know that Curt's boy was tortured and murdered because some white folks caught him with a picture of a (white) German girl. He also lets us know that African American servicemen coming back from every war have been discriminated against and abused as punishment for wearing their uniforms and medals. And the sad thing is this isn't just a metaphor, this is historical fact. Coot lays some serious history on us, and it's a history lesson we shouldn't ever forget.