The Library Journal of January 1, 1921 reported on the planting of a memorial tree at the Library of Congress on December 7, 1920 to honor four Library of Congress employees who lost their lives in World War I. The ceremony was presided over by Librarian of Congress Herbert Putnam. There were 89 Library of Congress male employees out of a total of 215 that enlisted during the war. The memorial tree still survives on the grounds of the Library of Congress Jefferson Building. The photographs above are from takomabibelot's Flickr photostream. There have, of course, been other library employees who have lost their lives in war while away from their library jobs during wartime. I am aware that both the Library of Congress and the New York Public Library have acknowledged such sacrifices of their employees during World War II. I am interested in finding more information about war memorials for library employees.