by Robert Lee Frost
Blood has been harder to dam back than water.
Just when we think we have it impounded safe
Behind new barrier walls (and let it chafe!),
It breaks away in some new kind of slaughter.
We choose to say it is let loose by the devil;
But power of blood itself releases blood.
It goes by might of being such a flood
Held high at so unnatural a level.
It will have outlet, brave and not so brave.
weapons of war and implements of peace
Are but the points at which it finds release.
And now it is once more the tidal wave
That when it has swept by leaves summits stained.
Oh, blood will out. It cannot be contained.
Update: This poem was published in 1928, in a collection called West-Running Brook.
I believe it is a response to the great Misssippi River flood of 1927, which killed and displaced thousands of people -- including, again, many African Americans. Herbert Hoover, one of the most incompetent Presidents in U.S. history, supervised the rescue efforts. His betrayal of African American victims of the flood led blacks to leave the Republican party, and may have changed the face of American politics.
Here is a PBS timeline detailing the events. The racial nastiness of the era makes this week's FEMA failure seem almost small.
With "blood," I think Frost is in some sense referring to the ugly human politics that came with (and followed) the disaster.