From a Post on The Conversation by:
In 2018, there were 143,518 library workers in the United States, according to data collected by the Institute of Museum and Library Services. While newer data isn’t available, the number is probably lower now, and recent history suggests more library jobs may be on the chopping block in the near future.
During the Great Recession, the economic downturn between late 2007 and mid-2009, thousands of librarians and other library staff lost their jobs. As local governments cut spending on libraries, the size of that workforce shrank to 137,369 in 2012 from 145,499 in 2008.