Background/Context/Biography
Encyclopedias, dictionaries, and handbooks are handy for getting a quick general overview of a specific topic. You can try searching in HOLLIS for your Subject plus the words encyclopedias OR dictionaries OR handbooks OR companion. Example:
Subject contains: Labor -- United States
AND
Subject contains: encyclopedias OR dictionaries
Limited to English
The Oxford Research Encyclopedias: American History offers numerous articles reviewing specialized topics. Each article has sections on Discussion of the Literature and on Primary Sources, together with a Further Reading bibliography and footnotes.
See specifically the articles under Labor and Working Class History.
What other things were happening at that time? The following books offer historical overviews of particular eras of American history
American decades 11 volumes. Covers, decade by decade, 1900-2009
HOLLIS Record
Internet Archive full text
Almanacs of American life:
Who's Who in Labor. 1976 Internet Archive Full Text
Who's who in labor; the authorized biographies of the men and women who lead labor in the United States and Canada and of those who deal with labor. 1946. Available in print and online in HathiTrust.
American National Biography is the standard American source for biographies of major figures. Can do searches of occupations and limit by date.
World Biographical Information System includes full text of thousands of biographical dictionaries accessible by name of biographee.
Biography and Genealogy Master Index (BGMI) indexes thousands of English-language biographical dictionaries and other compendia. Not full text; one must do HOLLIS searches for retrieved sources.
Additional sources in Finding Biographical Information.