The National Park System grew by one unit Tuesday as President Obama used his powers under the Antiquities Act of 1906 to create Fort Monroe National Monument in Virginia. With that declaration the president preserved a site integral to the history of slavery, the Civil War, and the U.S. military.

The president crafted the announcement as part of a series of executive actions "to put Americans back to work and strengthen the economy."

“Fort Monroe has played a part in some of the darkest and some of the most heroic moments in American history. But today isn’t just about preserving a national landmark- it’s about helping to create jobs and grow the local economy," the Democrat said in a prepared statement. "Steps like these won’t replace the bold action we need from Congress to get our economy moving and strengthen middle-class families, but they will make a difference."

Fort Monroe is the 396th unit of the park system, and the 22nd national park unit in the state of Virginia. The president's action marked the first time he has used the Antiquities Act to preserve a landscape, cultural, or historic site in the country.

First exercised by President Theodore Roosevelt in 1906 to designate Devil's Tower in Wyoming as the first national monument, the Antiquities Act has been used by 14 presidents since 1906 to protect some of the most unique natural and historic features in America, such as the Grand Canyon, the Statue of Liberty and Ellis Island.

According to an economic analysis commissioned by the Fort Monroe Authority in 2009, the implementation of the Fort Monroe Reuse Plan - the centerpiece of which envisions the preservation of the majority of buildings located within the 570-acre National Historic Landmark District as well as significant landscapes and viewsheds – will help create nearly 3,000 jobs in Virginia.

Fort Monroe, a historic fort in Virginia’s Tidewater region, played a pivotal role in the history of slavery in the United States. Built between 1819 and 1834, Fort Monroe has occupied a strategic coastal defensive position since the earliest days of the Virginia Colony. It was the place where Dutch traders first brought enslaved Africans in 1619.

During the Civil War, the fort remained in Union possession and became a place for escaped slaves to find refuge. Fort Monroe was the site of General Benjamin Butler’s “Contraband Decision” in 1861, which provided a pathway to freedom for thousands of enslaved people during the Civil War and served as a forerunner of President Abraham Lincoln’s Emancipation Proclamation of 1863.