Lovecraft Country is a series of books for Call of Cthulhu released between 1990 and 1998. Set in the 1920s, each provides background or adventures set along the Miskatonic Valley region of New England.
Books in the series:
1. Arkham Unveiled
2. Return to Dunwich
4. Tales of the Miskatonic Valley
5. Escape from Innsmouth
6. Adventures in Arkham Country
7. Miskatonic University
8. Dead Reckonings
9. Before the Fall
The two different version of the Miskatonic University Guidebook (1995, by Sandy Antunes & 2005, by Sam Johnson), while not titled as such, are also reasonably considered as part of this series.
In 1995 a truncated version of Arkham Unveiled was published as The Compact Arkham Unveiled - in this version the location numbers in Arkham were somewhat reorganized and the book's three scenarios were omitted.
A second edition of Escape from Innsmouth was published in 1997, which included one additional scenario ("The Crawford Inheritance") and another section for the "Raid on Innsmouth" scenario - "the Marsh Refinery".
The Arkham, Dunwich, and Kingsport guide books were reprinted in 2002-3; they were retitled as "H.P. Lovecraft's [city name]", with some slight additions or revisions to the text, including notes for using the books with the d20 Call of Cthulhu rules, and some new digital artwork. The scenario "A Little Knowledge" was cut from the Arkham book for use in the then forthcoming Miskatonic University Guidebook (see below).
Miskatonic University Press published two scenario collections - New Tales of the Miskatonic Valley (2008) and More Adventures in Arkham Country (2010) - which were explicitly intended to continue the series (Miskatonic Press being lead by the series chief architect Keith Herber).
In 2009 Arkham Now was published, updating Arkham as a setting for 'Cthulhu Now' play and was largely based on Arkham as described in Arkham Unveiled.
The Arkham Gazette, from Sentinel Hill Press, is a magazine intending to expand upon this setting, under license from Chaosium.