The Secret Custer Letter: Rediscovering Little Bighorn at 150 

Comparing the reports also reveals how Terry’s priorities shifted in the days following the battle. The June 27 report provides a detailed, almost chronological account of troop movements and events leading up to and immediately following the engagement. The July 9 report is far more concise, summarizing the actions of Custer and Reno before turning to practical concerns such as evacuating the wounded, communicating with military leadership, and securing supplies. Together, the reports capture a transition from immediate reaction to administrative response, illustrating how military leaders documented and managed the aftermath of one of the most consequential battles of the American West. 

While this blog highlights only a few differences between the reports, the full documents offer additional insights into how General Terry understood and communicated the aftermath of the Battle of the Little Bighorn. Digital scans of both reports are available online: June 26, 1876 – First Report and July 9, 1876 – Second Report.

Our search began with a newspaper article about a “secret” letter and a simple question: did the letter still exist in our collections? The answer, of course, was yes. But in the process of finding it, we were reminded that the true strength of archival collections lies not in a single remarkable document, but in the connections between records. Read together, the reports, letters, and reminiscences preserved within the MS 007 George Armstrong Custer Collection provide a more complete picture of the Battle of the Little Bighorn and its aftermath than any one document could alone. As we approach the battle’s 150th anniversary, these materials offer an opportunity to revisit familiar history through the voices of those who experienced, documented, and remembered it.