Henry Houghton originally started The Riverside Press in an old Cambridge building along the banks of the Charles River.

[5] Houghton chose to employ women as well as men as compositors, a radical decision which he said was influenced by the Victoria Press in England.

The composing-room is ninety feet long, the walls were adorned with engravings, the window-sills bright with flowers, embellishments said to be due to "refining feminine influence."

Beginning with the publication of the Stanford-Binet Intelligence Scale during World War I, Houghton Mifflin became increasingly involved in publishing standardized tests.

The clinical side of Riverside's business focuses on providing research and test materials for practicing professionals.