Professor Emeritus of History Carroll Engelhardt has published his fifth book, “By the Sweat of His Brow: The R. M. Probstfield Family at Oakport Farm.”

The book recounts the story of a prominent German pioneer family that farmed at Oakport (north of Moorhead, Minn.) from the mid-19th to the mid-20th centuries. Randolph Probstfield is remembered as the first truck farmer in the Red River Valley; for experimenting with varieties of fruit, vegetables, and small grains; and for serving as a Minnesota State Senator during the 1890s.

Engelhardt was featured in a Forum story by Tracy Briggs: “.”

Engelhardt is the author of four other books:

• “On Firm Foundation Grounded: The First Century of Å·ÃÀÊÓƵ,” for which he received the Red River Valley Heritage Society’s Historian Award
• “Gateway to the Northern Plains: Railroads and the Birth of Fargo and Moorhead”
• “The Farm at Holstein Dip: An Iowa Boyhood,” winner of the State Historical Society of Iowa’s 2013 Shambaugh Award for the Best Book Written about Iowa History the Previous Year
• “Concordia Fair Doth Stand: The College Begins its Second Century, 1991-2016”