Clifton's thesis, "When All Other Means Have Broken Down: Messenger Pigeons in the United States Army," is based on primary sources found in the archives of the U.S. Army Signal Corps Museum in Ft. Gordon, Georgia, as well as government documents and contemporary news articles. The messenger pigeon program ran from 1914 to 1957. Primary documentation provides insight on internal debates over the utility of the program as well as technical developments in pigeon communications systems. She argues that, despite being an innovation hundreds of years old, the messenger pigeon remained a useful and widely utilized technology in the U.S. Army. The end of the program was due not only to advances in electronic communications technology but also to an American culture that uncritically valued innovation more highly than technology-in-use. The research contributes to a broader debate on the proper focus of the history of technology.