Nearly 500,000 military personnel died during the U.S. Civil War. That’s almost half of all Americans who have ever died during wartime, and more than a hundred times more than died during the American Revolution, according to the latest estimates from the Department of Defense and the Department of Veterans Affairs. This Memorial Day, we decided to take a close look at the number of American service members who lost their lives during wartime in an effort to put their sacrifices into a broader perspective.

Not long ago, most Americans were likely to know an active military servicemember. But today, because of factors like the political cost of launching a military draft and the increasing automation and outsourcing of military-related tasks, fewer Americans have a personal connection to someone in the armed forces.

During World War II, about 12 percent of the total U.S. population were a part of the armed forces, according to Census Bureau and Department of Defense data. And while fewer servicemembers enlisted during the Vietnam War era, the conflict’s draft cut across American society, explains Gala True, a medical anthropologist and folklorist with the Department of Veterans Affairs and contributor to the Library of Congress’ Veterans History Project. She talks with veterans, primarily those who fought most recently in Afghanistan and Iraq, and explores ways to use narrative as a tool for mental health care. “Even though there’s so much talk about the opposition and difficult experiences that Vietnam veterans had coming home with protests, there was still a sense that people were very close to someone who had served or knew someone who had served,” she said.

Today, out of a nation of nearly 329 million people, 1.3 million Americans are in active duty military, and another 800,000 serve in the reserves, according to the Department of Defense.

That small figure influences the way the general public thinks about the cost of conflict, True says.

“In our society, we’ve seen this real shift,” she said. “Now, less than 1 percent of our population has served. The experience of going to war and coming home — we don’t have as much awareness.

We have a disconnect in our society about what’s going on, who has served and what they experienced.”

In many ways, Americans today feel removed from the Global War on Terror and military conflict, True said.

“So few have served, and that it’s very easy for people say now that ‘I didn’t want these wars,’ but that doesn’t mean that we aren’t all part of this,” she said.

The growing distance between Americans and the military has even changed the way we think and talk about the armed services, argues “The Atlantic” author James Fallows. In January, Fallows discussed his cover story, “Why Do the Best Soldiers in the World Keep Losing?: The Tragic Decline of the American Military,” with Margaret Warner on the NewsHour:

When I was a kid in the ’50s and ’60s and then older in the ’70s, American pop culture reflected a country familiar enough with its military to make fun of it at times. You had shows like “Gomer Pyle,” or “Hogan’s Heroes,” or “”McHale’s Navy.”

You had works of art like “South Pacific” or novels like “Catch 22″ and even movies like “MASH,” respected the importance of the military and the important things it did that were heroic in the large scale, like World War II, but it was still made of real people with their real foibles.

But we — now we have started to have this artificially reverent view of the military that’s also distant and disengaged.

After the Civil War, Americans were far from disengaged from the military. The war between the States and its terrible cost gave rise to new traditions and social norms in how citizens honored fallen soldiers. The casualty figures were so great, nearly every citizen was directly touched by the conflict. Families and friends of soldiers who lost their lives chose to honor the sacrifices of the fallen by spending a day of the year decorating their graves. Decorating the graves of fallen soldiers was a long-standing tradition, but the establishment of military cemeteries around the nation transformed the practice into a community event.

On May 30, 1868, the first official Decoration Day was declared by General John A. Logan and observed at Arlington National Cemetery. Volunteers decorated the graves of more than 20,000 Union and Confederate soldiers.

During World War II, decoration day was expanded and renamed Memorial Day to honor all Americans who died in military service. The day became a national holiday in 1971.

Editor’s note: This story was updated to remove a photo of Richard Arvine Overton, who was the oldest living World War II veteran at the time of publication. Mr. Overton died on December 27, 2018. He was 112 years old. This story was also updated in 2019 to update the number of active duty and reserve members of the military.