Can I access the archives of the Houghton Mifflin publishing company?

Houghton houses the historical archives of Houghton Mifflin Co., including editorial correspondence, contracts, and 19th- and 20th-century business papers, and they are open for research. The archive does not include copies of Houghton Mifflin’s publications.
There are several online finding aids for the cataloged parts of the collection in HOLLIS for Archival Discovery. An easy way to see a list of the major collections is to search for "Houghton Mifflin" and limit to Creator in the 2nd drop-down, below. (Go directly to that search)

"Houghton Mifflin" search limited to Creator

Much of the 20th-century part of the archive remains uncataloged, but readers are welcome to look at all parts of the collection here in the Reading Room. We are unable to search for particular items in the unprocessed parts of the collection on a reader’s behalf due to its size and because much of the collection is stored off-site.