Purpose: This interactive map visualizes the Civil War Defenses of Washington, DC — the ring of 68 earthen forts and 93 batteries that protected the Union capital from 1861–1865. Each fort is a clickable marker with rich historical narrative drawn from primary sources, NPS records, and contemporary accounts.
The idea to create this visualization was inspired by a framed period map of Civil War forts that hung in my last supervisor’s office before I retired.
Outer forts note: Beyond the main ring, the only major outer river forts were Fort Washington and Fort Foote. Fort McHenry (Baltimore) defended Baltimore harbor and was not part of the Washington defenses.
Developed and researched by Grok (xAI) · April 2026 · Corrections, suggestions, or additional sources are welcome via GitHub Issues