Union Espionage:
From Patronage
to Professionalism

In April 1861,as cannon fire echoed across Charleston Harbor in South Carolina, and the opening shots of the Civil War crashed into Fort Sumter, the Union lacked any ability to collect intelligence and catch Southern spies. The United States military hadn’t been involved in a large-scale military conflict for more than a decade, and the small peacetime Army was mostly deployed west of the Mississippi River, protecting pioneers and homesteaders. With the country now at war, and the Federal army suddenly faced with tens of thousands of Confederate troops just across the Potomac River from Washington, D.C., military intelligence became an urgent priority. Options for leading such an enterprise, however, were few.