OpenTwo archives, queried live.
Every record below comes from The Met or Smithsonian Open Access and was filtered on that archive’s own rights field before it reached this page. 24 shown for “Union prisoner of war cover” — 64 records examined, 11 dropped by the rights gate.
Archives queried 2026-09-01 01:06 UTC · fetched live for this request
isPublicDomain field is true for this object.metadata_usage.access reads CC0 — a waiver, not an expired term.
Prisoners from the Front
Winslow Homer · 1866
Union Prisoner-of-War Cover
Artist not stated in the record · October 23, 1863
The Conquest of Naples by Charles of Durazzo
Master of Charles of Durazzo · 1381–82
Union prisoner of war cover
Artist not stated in the record · May 22, 1865
The Cloisters Apocalypse
Artist not stated in the record · ca. 1330
Union Prisoner-of-War Cover
Artist not stated in the record · 1864
Don Gaspar de Guzmán (1587–1645), Count-Duke of Olivares
Juan Bautista Martínez del Mazo · ca. 1636 or later
Union Prisoner-of-War Cover
Artist not stated in the record · 1864
An Egyptian Peasant Woman and Her Child
Léon Bonnat · 1869–70
Union Prisoner-of-War Cover
Artist not stated in the record · 1864
Photographic Views of Sherman's Campaign
George N. Barnard · 1860s
Union prisoner of war cover
Artist not stated in the record · May 12, 1865
Mars and Venus United by Love
Paolo Veronese (Paolo Caliari) · 1570s
Union prisoner of war cover
Artist not stated in the record · Oct. 26, 1864
The Third-Class Carriage
Honoré Daumier · 1864
WWII German POW free mail post card
Artist not stated in the record · October 16, 1943
Smallsword with Scabbard and Case
Michael Barnett · hallmarked for 1798–99
Confederate Prisoner-of-War Cover
Artist not stated in the record · Postmark: April 16, 1863
The "Kearsarge" at Boulogne
Edouard Manet · 1864
Cover
Artist not stated in the record · c. 1944
Circus Sideshow (Parade de cirque)
Georges Seurat · 1887–88
Prisoner of war air letter sheet
Artist not stated in the record · 1939-1945
Plaque with equestrian ọ́bà (king) and attendants
Ìgùn Ẹ́rọ̀nwwọ̀n (brass-casting guild) artists · ca. 1540–70
Prisoner of war air letter sheet
Artist not stated in the record · 1939-1945
Where these records came from.
Two archives are wired, and only two. Each one is filtered on its own rights field — never on a title match, and never on the presence of an image file.
- The Met Collection API (Open Access)Rights field:
isPublicDomain. 44 matched · 24 examined · 2 dropped by the rights gate. Kept only where isPublicDomain === true and a file URL was published.12 shown - Smithsonian Open Access API (api.si.edu)Rights field:
content.descriptiveNonRepeating.metadata_usage.access. 2869510 matched · 40 examined · 9 dropped by the rights gate. Kept only where metadata_usage.access === "CC0" and an image resource was published.12 shown
These figures describe the pass run at 2026-09-01 01:06 UTC, during this request. A completed pass is kept for 24 hours and replayed for an identical search, which is what keeps repeated queries inside Smithsonian’s 30-requests-per-hour allowance. A pass in which either archive failed to answer is never kept — an outage must not be replayed as though it were a finding about the catalogue.
Wikimedia Commons and the Library of Congress are deliberately not wired. Wikimedia was confirmed, on a live query, to return CC-BY material inside the same result set as genuine public domain works, and filtering it safely has not been designed yet. loc.gov was blocked by bot detection during the source evaluation, so its rights vocabulary has never been observed — and nothing here is built on a field nobody has read.
An image file is a rights claim. It never travels without its field.