Stearns eventually was able to write his own work focused on the English refugees, Congregationalism in the Dutch Netherlands (1940), which won the Frank S. Brewer Prize from the American Society of Church History.
Stearns spent the 1936–1937 academic year as the head of the history department at Lake Forest College and then settled in Urbana to teach at the University of Illinois there, becoming a full professor in 1948.
[3] Stearns spent a year teaching at Ghent University in Belgium; on his return he published (with George Frederick Frick) Mark Catesby: The Colonial Audubon (1961).
While in London, Stearns met Walter Muir Whitehill; on their return to Boston, he introduced him to the circle of Harvard colonial historians including Perry Miller, Carl Bridenbaugh, and Clifford K. Shipton.
Stearns was a lifelong friend and colleague of Shipton's, serving together on the Council of the Institute of Early American History and Culture and visiting each other when possible.