Explain why the Vietnam Memorial is a symbol of national unity?

I agree with pohnpei in that perhaps national unity is the
wrong way to describe it.  Unifying in that those who were for or against the war could
nevertheless agree on the fact that the loss of 58,000 Americans was a tragedy, and that
they should be honored for their sacrifice.  Some have argued that it was a healing
symbol by allowing both civilians and veterans to connect with those they lost in the
war, and to leave offerings, poems, shrines, etc. in a final connection with them (a
stunning exhibit of items left at the Wall is on permanent display at the Smithsonian
Museum of American History in Washington DC).

The Vietnam
War was a very painful chapter in American history and the Wall has allowed many
Americans to begin, at least, to process and heal from that
grief.