The poem "Facing It" by Yusef Kumunyakaa is about a Vietnam War veteran. In this poem he goes to visit the memorial, and he seems to go often. While there he seems to struggle with the idea that he is there. Meaning he's a part of it yet he is not. He states "I'm stone. I'm flesh." Which could mean he realizes he's alive but he feels like his name should be there. Possibly he doesn't think he deserved to live when so many others died. He pays special attention to Andrew Johnson, probably someone he knew during the war, and judging by the flashback, saw die. Also I feel this sentence "half-expecting to find my own in letters like smoke" reinforces what I feel. It's as if a large part of him did in fact die in Vietnam.
Also "I'm stone. I'm flesh" could be interpreted another way. If you look at the sentence before it where it says:
" I said I wouldn't, dammit: No tears. I'm stone. I'm flesh."
By "stone" he could mean that he is strong and powerful. He can take whatever life throws at him and whatever it takes away. He didn't want to succumb to those emotions. He wanted to be strong for himself and those he fought with.