Though it was built in response to an earlier conflict, Fort Sumter in the Charleston Harbor was the birthplace of the American Civil War. Tensions between the North and South had been high for years, but the situation didn’t escalate into an all-out war until Confederates took the Union-occupied garrison in April 1861. Here are 10 things you should know about Fort Sumter, its origins, and its ever-relevant legacy.

1. Fort Sumter was named after a Revolutionary War hero.

General Thomas Sumter (1734-1832) served in the French and Indian War as an officer in the Virginia militia. He later relocated to South Carolina, where he attained national hero status once the American Revolution began. Sumter’s guerilla-style attacks kept the British on their toes and helped him score a surprise victory at the Battle of Blackstock's Farm in present-day Union County, South Carolina. Following the war, Sumter represented the state on Capitol Hill as both a U.S. congressman and, eventually, a senator. Here’s a fun tidbit for college sports fans: Ever wonder why the University of South Carolina’s athletic teams are called “The Fighting Gamecocks?” It’s a tip of the hat to Sumter, who was nicknamed “The Carolina Gamecock” during the Revolution because of his rooster-like vigor (or possibly his ego).

2. The War of 1812 spurred Fort Sumter’s development.

The War of 1812 proved that many of America’s coastal cities were vulnerable to attacks from foreign navies. So in 1816, Congress appropriated more than $800,000 (equal to about $14.5 million in today’s dollars) for new seaside fortifications. Although construction on Fort Sumter didn’t actually start until 1829, its origins can be traced back to this development.

3. Fort Sumter sits on an artificial island.

Fort Sumter was built on an artificial island.Thinkstock/Getty Images

When the plans for Fort Sumter were approved in 1828, its designers envisioned “a pentagonal, three-tiered, masonry fort with truncated angles to be built on the shallow shoal extending from James Island.” They had their work cut out for them: Not only did the sandbar get totally submerged at high tide, but it also tended to shift around in the current. Before the fort could go up, more than 109,000 tons of rock had to be deposited at the site to create a stable artificial island.

4. Construction at Fort Sumter was held up over a legal dispute.

Progress on Fort Sumter stalled from 1834 to 1841, thanks to questions about land ownership and, more broadly, federal authority. Trouble started when William Laval, a private citizen, claimed he owned the shoal upon which the fort was being built. At the same time, many of South Carolina’s elected officials believed the decision to build a military garrison in the Charleston Harbor infringed on their state’s rights. The matter was finally resolved in ’41, when the Palmetto State gave the title on that disputed terrain to the federal government.

5. Fort Sumter wasn’t finished when the Civil War began.

South Carolina seceded from the Union on December 20, 1860. Six days later, Major Robert Anderson, a Union loyalist who’d been put in command of Charleston’s Federal troops, gathered his men and ferried them to Fort Sumter, which could be more easily defended than any of the harbor’s other fortifications. At the time, several components of their chosen refuge remained unfinished. Portions of the gunrooms, barracks, and quarters were missing when Anderson and company arrived—and while the facility was designed to house 135 cannons, only 15 had been set up there.

6. There were no casualties in the 1861 attack on Fort Sumter—but someone died in the aftermath.

A Civil War cannon at Fort Sumter.Martina Birnbaum/iStock via Getty Images

Stranded on the island, Anderson and his forces languished at Fort Sumter until the spring of 1861. Hostilities escalated that April, when President Abraham Lincoln tried to resupply the garrison. In response, Confederate gunmen led by General P.G.T. Beauregard started firing at Fort Sumter on the morning of April 12, 1861. The attack commenced just after 4:30 a.m. Some 34 hours later, on April 14, Anderson surrendered. Not a single human life was lost during the bombardment, but as the Union Flag was being lowered, Private Daniel Hough of the 1st U.S. Artillery was unintentionally killed by a ceremonial cannon-shot.

7. Another battle erupted at Fort Sumter in 1863—and it was much bloodier.

The battle—a follow-up to a failed naval assault—took place on September 7 and 8, 1863. Four hundred Union sailors and marines advanced on the garrison, which was believed to be largely unoccupied. But unfortunately for the Union troops, it wasn’t. Some 300 Confederates attacked them from within the structure. “Two-thirds of the amphibious [Union] force escaped, but nearly two dozen of them were killed or wounded and more than a hundred were captured on the face of the fort,” recounts the National Park Service website. “No Confederates were injured.”

8. When Fort Sumter was recaptured, Anderson got to raise the Union Flag.

Raising the flag over Fort Sumter.Wikimedia Commons // public domain

The Second Battle of Fort Sumter may have been a Confederate victory, but over the next 15 months, from September 1863 through February 1865, the Union shot 50,000 projectiles at the building. Then, on February 18, 1865, Charleston was surrendered to the Union. At the invitation of Lincoln’s War Department, Robert Anderson made the trip down to Fort Sumter from his New York City home. On April 14, 1865—the same day Lincoln was fatally shot at the theater—Anderson hoisted the Union flag over the garrison he’d lost exactly four years earlier.

9. Fort Sumter was upgraded for later wars.

After the battered fort was patched up in the 1870s, Fort Sumter was mostly used as a lighthouse until the Spanish-American War began in 1898. To prepare for a potential enemy assault, it was fitted with a set of long-range rifle cannons. The fort was again made battle-ready for World Wars I and II. During the latter, four rapid-fire 90-millimeter anti-aircraft guns were installed.

10. Fort Sumter is part of a National Historical Park.

Fort Sumter was deactivated in 1947 and became a national monument the following year. On March 12, 2019, its status was revised: Today, the human-made island and its famous occupant are part of the newly designated Fort Sumter and Fort Moultrie National Historic Park. (Fort Moultrie is an older facility that was the site of a 1776 Patriot victory in the American Revolution.) Fort Sumter attracts thousands of visitors every year and on April 14, 2015, reenactors gathered to celebrate the 150th anniversary of Robert Anderson’s 1865 flag raising ceremony.