Shrouded in mystery since Appomattox, the critical role of Upper Difficult Run in Fairfax County, Virginia as a staging area for Confederate guerrillas and a laboratory for innovations in asymmetric warfare has gone largely undocumented.

This work is an attempt to piece together fragments of evidence into a coherent story about the ways that people, places, and psychologies self-organized into a spatial domain rich in hidden history.

Confederate guerrilla John Mosby and his forces tied up 50,000 Union troops in Northern Virginia during the last two and a half years of the Civil War. He and his men marauded deep into Federal lines. They suffered relatively few casualties and did immense damage to both the Union psyche and supply chain.

As told, the Mosby story involves every space around Difficult Run, but rarely answers the critical question of how the guerrilla chieftan utilized uneven terrain and modest farms within the basin itself.

Years of research have produced an undeniable conclusion: Mosby and his men harnessed thickets, unlikely avenues, friendly farms, and a collection of bridle paths into assets for an irregular campaign. Slender trails that rarely appeared on maps and left the faintest traces on the muddy soil of Fairfax County became lethal highways in this microwar.

By studying advanced satellite imagery, historic maps, official records, extant economic data, first person narratives, genealogies, folklore, geology, geography, sociology, ethnography, and political history through a bifocal lens of spatial analysis and military studies, the shape and dimension of this lost war and the mysterious bridle paths on which it was fought appears from a murky past 160 years distant.