His book The Day of the Cattleman, a regional study of cattlemen in Montana and Wyoming in the mid-nineteenth century, was his most critically acclaimed work.
She had just left the St. Paul, Minnesota home of the granddaughter of John Henry Hammond, a general during the Civil War on the staff of William Tecumseh Sherman and, later, an inspector for the Bureau of Indian Affairs.
Kane told Dr. Osgood that in the papers of General Hammond, she had found a bundle wrapped in an 1805 copy of the Washington, D.C. National Intelligencer.
After a prolonged federal legal battle over ownership of the papers involving Hammond's descendants, the Minnesota Historical Society, Yale University, and the National Archives and Records Administration, the papers ended up in the Western Americana Collection at Yale University's Beinecke Rare Book & Manuscript Library where Osgood was able to finish editing the collection.
After 30 years at the University of Minnesota, Dr. Osgood retired to Wooster, Ohio where he occasionally lectured at the College of Wooster, continued to write, and was an Independent Study Advisor to scores of students, including Pulitzer Prize winner Susan Q. Stranahan.