An Israeli librarian using Wikipedia (publicity photo for the project)
|Inaugurated||15 January 2016– 23 January 2016|
|Next event||15 May 2020– 5 June 2020|
The first #1Lib1Ref campaign coincided with the 15th anniversary of the founding of Wikipedia in January 2016. Based on the premise of One Librarian, One Reference, organizers estimated that if each librarian on the planet spent 15 minutes adding a citation, the combined effort would eliminate English Wikipedia's backlog of 350,000  notices. The inaugural, weeklong event ran from 15–23 January 2016, and employed the hashtag #1lib1ref on various social media platforms.
The inaugural campaign ended with 1,232 revisions on 879 pages, by 327 users in 9 languages, using the hashtag #1lib1ref in the edit summary; these numbers likely underestimate the overall impact, since many participants were observed omitting the hashtag from edit summaries. On Twitter the #1lib1ref hashtag was used in over 1,100 posts by over 630 users. 
The campaign has been revived as an annual celebration of Wikipedia's birthday, expanding into a three-week event in subsequent years. The 1Lib1Ref campaign is part of the Wikimedia Foundation's GLAM outreach strategy to involve librarians in the improvement of Wikipedia.