John Leonard Jennewein was an afficionado of the American West with a passion for preserving and sharing the past through his various roles as historian, educator, author, and museum curator.
Born 5 June 1910 in Bath, South Dakota, the son of Fred and Lena Jennewein grew up on the HAT ranch near Bison. He married Marjorie Bullock in 1933, and they had two daughters, Linova and Sylvia.
Jennewein held assorted jobs throughout South Dakota, beginning as a rural schoolteacher near Bison. After graduating from Northern State Teachers College at Aberdeen in 1935, he relocated to Pierre to work as district director of employment for the Work Projects Administration. Throughout the 1940s and early 1950s, he served in the United States Army, as state director of recreation for the Federal Works Agency in Mitchell, chief clerk of the post engineers at the Black Hills Ordnance Depot in Igloo, and district property officer for the Bureau of Reclamation at Huron. In 1953, Jennewein and his family settled in Mitchell, where he taught history and English at Dakota Wesleyan University until his death in 1968.
Through his father, an avid collector of cowboy memorabilia, Jennewein had gained an interest in western history. He authored several publications, including Calamity Jane of the Western Trails, Prelude to Barbed Wire, and Black Hills Book Trails. He also co-edited Dakota Panorama, a collection of historical essays commemorating Dakota Territory’s centennial.
As executive secretary of the Friends of the Middle Border, Jennewein tirelessly collected and documented artifacts for the organization’s museum in College Hall on the Dakota Wesleyan campus, both before and after fire destroyed the building in 1955. Now named the Dakota Discovery Museum, the facility is located near the Dakota Wesleyan campus, where the Jennewein Western History collection is housed at the university’s McGovern Library.
Jennewein belonged to numerous historical organizations and received several awards during his lifetime. A noted lecturer, he was frequently called upon to emcee events across the state. The City of Mitchell named Jennewein Park in his honor in 1968, and he was inducted into the South Dakota Hall of Fame in 1978.
J. Leonard Jennewein died on 4 January 1968 and is buried in the American Legion Cemetery in Mitchell, South Dakota.