USA
Digital Public Library of America
The Digital Public Library of America (DPLA) brings together more than 8 million digitized items from America’s libraries, archives, and museums including around 5,000 items related to the First World War.
Prints & Photographs Online Catalogue Photo Collection, Library of Congress
The Library of Congress’ online collection of photos.
For an overview of the LoC collections on WWI, see “A Guide to World War I Materials” at
http://www.loc.gov/rr/program/bib/wwi/wwi.html
In particular: World War I Posters, Library of Congress
A collection of approximately 1,900 posters created between 1914 and 1920. The majority of the posters were printed in the United States. Posters from Australia, Austria, Belgium, Canada, Germany, Great Britain, Italy, the Netherlands, and Russia are also included.
http://www.loc.gov/pictures/collection/wwipos/
The Veterans History Project, American Folklife Center (Library of Congress)
A project collecting, preserving and making accessible the personal accounts of American war veterans.
American Leaders Speak: Recordings from World War I and the 1920 Election, Library of Congress
The Nation's Forum Collection from the Motion Picture, Broadcasting, and Recorded Sound Division consists of 59 sound recordings of speeches by American leaders. The speeches focus on issues and events surrounding WWI and the subsequent presidential election of 1920.
http://memory.loc.gov/ammem/nfhtml/nfhome.html
The Stars and Stripes: The American Soldiers' Newspaper of World War I, 1918-1919, Library of Congress
The complete edition of the newspaper, “The Stars and Stripes,” published in France by the United States Army from February 1918 to June 1919. The eight-page weekly featured news, poetry, cartoons and sports coverage.
http://memory.loc.gov/ammem/sgphtml/sashtml/sashome.html
National Archives Homepage, US National Archives and Records Administration
A website containing access to some of the US’s important national documents and material.
The Deadly Virus: The Influenza Epidemic of 1918, US National Archives and Records Administration
An online archive of documents and photos showing the course and consequences of the 1918 Spanish flu epidemic that killed 50 million people worldwide
http://www.archives.gov/exhibits/influenza-epidemic/
Eyewitness, American Originals from the National Archives, US National Archives and Records Administration
A small collection of eyewitness accounts from key events in the past 150 years, including two on WWI.
http://www.archives.gov/exhibits/eyewitness/
Panoramic Photographs from the National Archives, US National Archives and Records Administration
A small sample of the wide variety of panoramic images in NARA’s still-picture holdings. The exhibit covers the period from 1864 to 1937, but the vast majority of images date from the WWI era.
http://www.archives.gov/exhibits/panoramic_photography/panoramic_home.html
Collections Search Center, Smithsonian Institution
A collection of more than 7.7 million catalogue records with 568,000 images, video and sound files, electronic journals and other resources from the Smithsonian’s museums, archives and libraries.
http://collections.si.edu/search/
New York Public Library Digital Gallery, New York Public Library
A collection of more than 700,000 images digitized from the New York Public Library's vast collections.
http://digitalgallery.nypl.org/nypldigital/index.cfm
World War I Photograph Albums and Postcards, The New York Public Library Digital Collections
This collection from the New York Public Library consists of four exhibitions titled, Under the Red Cross flag at Home and Abroad: Base Hospital Unit #44 and Evacuation Hospital #5, German World War I Photographs and Postcards, Photographs of World War I Battlefields, Captured German Installations and Allied Installations, and Usines Delahaye; collaboration des femmes a la defense nationale, guerre europeenne.
Campaign Atlas to the Great War, West Point Academy, Department of History
A database of campaign and battle maps from WWI.
http://www.westpoint.edu/history/SitePages/WWI.aspx
The National Historical Geographic Information System (NHGIS), University of Minnesota
The National Historical Geographic Information System (NHGIS) provides, free of charge, aggregate census data and GIS-compatible boundary files for the United States between 1790 and 2010.
Military Resources: World War I, US National Archives
A collection of online resources and links to external websites containing photos, background articles, educational resources and biographies relating to primarily American involvement in WWI.
http://www.archives.gov/research/alic/reference/military/ww1.html
The University of Colorado at Boulder Libraries' digital World War I collection
The University of Colorado at Boulder Libraries' World War I Collection Online offers a rich array of primary-source material related to the First World War. The digital collection consists of over 1,100 titles (55,000+ pages), mainly published during the war years, and represents a wide range of formats, genres, geopolitical units, and subject matter.
http://cudl.colorado.edu/luna/servlet/s/g4l4ln
The National WWI Museum and Memorial, Kansas City
The Online Exhibitions of the National WWI Museum and Memorial provide articles, images and other primary sources on a diverse range of topics on United States First World War history.
https://www.theworldwar.org/explore/exhibitions/online-exhibitions
World War I Collection, University of Wisconsin Libraries
The World War I Collection from the University of Wisconsin Libraries features primary sources. Materials from all fronts in Europe can be found in this collection.
https://search.library.wisc.edu/digital/AWWIColl
Online Collections Database, The National WWI Museum and Memorial
The online collections database allows users to search the digital records of the museum’s global collection that began in 1920. With new editions added monthly, this collection has many diverse images and resources.
https://www.theworldwar.org/explore/online-collections-database
American Libraries During World War I, University of Wisconsin-Madison Libraries
This collection consists of materials relating to the role of libraries during the period of American involvement in World War I, from 1917 to 1918.
https://digital.library.wisc.edu/1711.dl/WWILibrary
American War Posters from the First World War, Bancroft Library
168 digitized American posters from World War I, hosted by Bancroft Library.
World War I Sheer Music, Brown University Library Center for Digital Scholarship
In association with the John Hay Library, Brown University’s collection of World War I sheet music and cover art aims to preserve the many types of popular music in the United States during the First World War.
https://library.brown.edu/cds/sheetmusic/ww1/index.html
Sheet Music Collection, University of Missouri Kansas Digital Special Collections
The University of Missouri-Kansas provides digitized original sheet music from the United States. Sheet music for both World Wars can be found in this collection.
https://dl.mospace.umsystem.edu/umkc/islandora/object/umkc:sheetmusic
Recipe for Victory: Food and Cooking in Wartime, University of Wisconsin Libraries
With sources provided by the University of Wisconsin Libraries, the unique “Recipe for Victory: Food and Cooking in Wartime” collection provides books and documents outlining the importance of food and recipes used on the British and American homefronts during the First World War.