German Soldiers Tending to an Injured Dog at a Field Hospital For Dogs During World War 1

German soldiers tending to an injured dog at a field hospital for dogs during World War 1.

Source: Royal Library, Denmark.

Hand-Colored Stereoview Portrait of a Woman Praying Titled "Evening Prayers" (1850′s/1860′s)

Hand-colored stereoview portrait of a woman praying titled "Evening Prayers," probably British, c. 1850′s/1860′s.

Source: Rijksmuseum.

Daguerreotype Portrait of a Woman Named Mary Ann Bartlett Posing With a Stack of Books (1850′s)

Daguerreotype portrait of a woman named Mary Ann Bartlett posing with a stack of books, c. 1850′s.

Source: Library of Congress.

A Group of Italian POWs in a Prison Camp During World War 1

A group of Italian POWs in a prison camp during World War 1, location unknown.

Source: Royal Library, Denmark.

View of Attendees at the Opening Night of the Masonic May Festival in Washington, DC (1906)

View of attendees at the opening night of the Masonic May Festival in Washington, D.C., May 23, 1906. By the George R. Lawrence Company.

Source: Library of Congress.

Daguerreotype Portrait of a Man Named Tsow Chaoong Posing with a Daguerreotype and Fan (1847)

Daguerreotype portrait of a man named Tsow Chaoong posing with a daguerreotype and fan, 1847.

Source: Metropolitan Museum of Art.

Hand-Colored Stereoview Portrait of a Woman Playing a Guitar by Italian-Swiss Photographer Giorgio Conrad (1850′s/1860′s)

Hand-colored stereoview portrait of a woman playing a guitar by Italian-Swiss photographer Giorgio Conrad, c. 1850′s/1860′s.

Source: Rijksmuseum.

Stereoview of People, Buildings, and a Hydrant Shooting Water Into the Air on Independence Day in Providence, Rhode Island (1873)

View of people, buildings, and a hydrant shooting water into the air in Providence, Rhode Island, July 4, 1873. By the photography firm Manchester Brothers.

Source: Boston Public Library.

View Possibly Showing Dead, Dying, or Pinned Down Soldiers in No Man’s Land During World War 1 (1910's)

View possibly showing dead, dying, or pinned down soldiers in no man’s land during World War 1, location unknown.

SourceSan Diego Air and Space Museum.

Portrait of American Soldiers From Company C of the 115th Infantry Regiment in Camp McClellan Near Anniston, Alabama (1918)

Portrait of American soldiers from Company C of the 115th Infantry Regiment in Camp McClellan near Anniston, Alabama, April 1, 1918. By Novelty Photo Company.

Source: Library of Congress.