He donated all the files of the Commission for Relief in Belgium, the U.S. Food Administration, and the American Relief Administration, and pledged $50,000 as an endowment (equivalent to $781,478 in 2021). Scholars were sent to Europe to collect pamphlets, society publications, government documents, newspapers, posters, proclamations, and other ephemeral materials related to the war and the revolutions that followed it. The collection was renamed the Hoover War Library in 1922 and is now known as the Hoover Institution Library and Archives.[93] During the post-war period, Hoover also served as the president of the Federated American Engineering Societies.[94][95]

1920 election
Further information: 1920 United States presidential election
Hoover had been little known among the American public before 1914, but his service in the Wilson administration established him as a contender in the 1920 presidential election. Hoover's wartime push for higher taxes, criticism of Attorney General A. Mitchell Palmer's actions during the First Red Scare, and his advocacy for measures such as the minimum wage, forty-eight-hour workweek, and elimination of child labor made him appealing to progressives of both parties.