Here is the link to Purdue Owl's Chicago Style Manual.
A multidisciplinary database of more than 8,500 fulltext periodicals with pdf content going back as far as 1887. Includes indexing and abstracting for more than 12,500 periodicals.
Humanities and Social Sciences Retrospective is a bibliographic database that includes citations for more than 1,300,000 articles, inlcuding book reviews, from English-language periodicals. Coverage 1907-1984
JSTOR is a shared digital library that includes the fulltext of more than 2,000 academic journals, dating back to the first volume published. Coverage varies depending on the journal title.
Provides full-text access to more than 400 scholarly journals in the arts and humanities, social sciences, and mathematics. Coverage varies by publication; the earliest date of inclusion is 1990.
Access to citations to over 3 million articles from approximately 375 leading magazines covering the years 1890-1982. Coverage 1890-1982