<p>"Walter Reed Hospital Flu Ward". 
</p>
Photo of Walter Reed Hospital, Washington, D.C., during the great Influenza Pandemic of 1918 - 1919, also known as the "Spanish Flu".  Patients are set up in rows of beds on an open gallery, seperated by hung sheets.  A nurse wears a cloth mask over her nose and mouth.
Harris &amp; Ewing photographers
Not dated, probably during the height of the epidemic, 1918 - 1919
Photo by Harris &amp; Ewing via Library of Congress website at <a rel="nofollow" class="external autonumber" href="http://hdl.loc.gov/loc.pnp/hec.14088">[1]</a>; converted from TIFF to .jpg and border cropped before upload