In the years before the start of the Civil War, marked by the Confederate attack on Fort Sumter, the U.S. military was already constructing defensive fortifications around major cities, often along coasts. This was an effort to better protect against foreign invasion after the War of 1812 exposed vulnerabilities. (These are the oldest military forts built before America was a country.)

The impending war between the states accelerated the building of more forts to defend key cities, supply lines, and transit routes. Over 60 forts were built just around Washington D.C. alone as neighboring states seceded or had Confederate sympathies.

Traditionally brick or masonry forts were standard, but new rifled cannons made those obsolete. This led to many inexpensive, quickly built earthwork forts that could better withstand cannonball impacts.

While many forts were destroyed during the war or after, some still stand today. To determine 33 Civil War forts that you can visit, 24/7 Tempo compiled military fortifications that were used during the Civil War from sources including the National Park Service as well as state and regional tourism websites. 

Click here to see 33 Civil War forts you can still visit

We focused on accessible sites that are open to the public. Some contain original structures or ruins, as well as reconstructed facilities, replicas, museums, and reenactments on the forts’ original grounds. 

Though not a comprehensive list, these sites include both masonry and earthworks forts, some predating the war and others hastily built during it. Many remained in military use in later wars with updated fortifications, while others were abandoned and later recovered. Most are now part of state or national parks commemorating this history. (These were the largest battles of the Civil War.)