When Lance Cpl. Niall Coti-Sears decided to join the U.S. Marine Corps, he was emulating a hero.

“He wanted to follow in his grandfather’s footsteps,” Coti-Sears’ mother, Susan Coti, told The Unknown Soldiers.

Niall’s grandfather, Col. William Coti, served in the Marines for more than 30 years. Before two tours in Vietnam, he fought in the bloody 1950 Battle of Chosin Reservoir — one of the Korean War’s defining struggles.

The heroes who clashed with Communist Chinese forces for 17 days in freezing conditions are known as “The Chosin Few.”

Niall, who was home-schooled by his grandparents for two years, spent many hours learning in their basement, which his parents said resembles a Marine Corps museum. Although Col. Coti never told his grandson to join the military, young Niall would often put on old uniforms and pretend he was in combat.

“One time I said, ‘Niall, the gun jammed and the enemy is getting close, what are you going to do?’ ” Col. Coti recalled. “He picked up a grenade and threw it.”

One day, Niall decided to become a Marine.

“Poppy, I want to be like you,” he said. When the teenager told his parents, both feared for his safety.

“My initial reaction was that I was completely against it,” Niall’s father, Paul Sears, said. “Not because of the Marine Corps or the military, but because of the way the world is today.”

But when the aspiring Arlington, Va., warrior paid a visit to his father in Baltimore, Paul could see the focus in his son’s eyes.

“I was 100 percent behind him,” the Marine’s father, who now lives in Arizona, said.

Still, both parents hoped Niall could avoid Afghanistan or Iraq’s front lines.

“We begged him not to choose infantry,” Niall’s mother said. “We said, you could do anything; why would you want to go to Afghanistan as an infantryman?”

But that’s exactly the path Niall, who grew up hearing his grandfather’s war stories, chose.

“He was just ... a really fearless guy,” Susan said.

“I believe that he needed to be part of something that was a lot larger than he was,” Paul said.

Before leaving for Afghanistan, Niall spoke to fourth graders at the Washington, D.C., school where his mom teaches.

“One of the boys asked him if he was afraid,” Susan said. “He said no ... he really believed it was something he needed to do.”

Niall deployed to southern Afghanistan with the 1st Battalion, 7th Marine Regiment in March. He was in frequent communication with his family until about Father’s Day, when he went behind Taliban lines for a dangerous mission.

“That’s when I got worried,” his father said. “And when his birthday came, I got really worried.”

On June 21 — Niall’s 23rd birthday — his mother got a box of flowers.

“Just because you’re always here for me, mom,” Niall’s card read.

Two days later, Niall was killed in Afghanistan’s Helmand Province. His mom, dad and grandfather said he stepped on an enemy improvised explosive device.

Commanders informed the Marine’s parents that not long before his death, Niall was in a ferocious firefight. Just like the pretend battle in his grandfather’s basement, Niall picked up grenades and fearlessly hurled them toward the enemy.

“Everyone who knew Niall knew his greatness,” Niall’s platoon commander, 2nd Lt. Kenneth Conover, wrote to the family.

Col. Coti is immensely proud of his grandson. But pride doesn’t erase the pain he and other members of Niall’s family are experiencing.

“It’s been a complete blur,” Niall’s dad said six weeks after his son was killed. “To me, it just happened yesterday.”

“It’s hard to believe he’s gone,” the Marine’s mother said.

Niall was laid to rest at Arlington National Cemetery, where he is surrounded by heroes of the battles in which his grandfather once fought.

“He was always looking out for other people’s welfare,” Col. Coti said.

While delivering Niall’s eulogy, Paul read a Buddhist quotation that inspired his son.

“The greatest achievement is selflessness,” it begins.

Like Col. William Coti in Korea and Vietnam, Lance Cpl. Niall Coti-Sears selflessly stepped forward to serve in Afghanistan. In choosing to his risk his life for others, a proud grandson didn’t just emulate a hero. He became one.

The Battle of Antietam

It remains the single-bloodiest day of fighting on American soil and it was fought 150 years ago this week in the Civil War: The Battle of Antietam began Sept. 17, 1862, when Union forces commanded by Maj. Gen. George B. McClellan clashed with Confederate rivals under the direction of Gen. Robert E. Lee in a cornfield at Sharpsburg, Md., or Antietam.

The bitter battle raged around such spots now burned into American history books as Dunker Church and the Sunken Road. Marked by attacks and counterattacks, the pitched 12 hours of fighting claimed at least 23,000 wounded, missing and disappeared.

When the roar of combat was over, Lee’s limping Army of Northern Virginia was forced to withdraw on Sept. 18 amid skirmishing to cross the Potomac River southward to the safety of Virginia’s Shenandoah Valley.

Neither side could claim this as an outright tactical victory. Yet Antietam was a turning point in the Civil War and seized upon as a strategic victory for the Union. The federal forces, though they failed to pursue Lee’s retreating army, had shown it could stop the savvy Confederate commander’s opening invasion of the North.

Historically, the battle’s aftermath gave President Abraham Lincoln the moment he needed to roll out his preliminary Emancipation Proclamation. Within days, Lincoln would declare that the Civil War had the double aim of keeping the Union intact and abolishing slavery.

The Associated Press, reporting on the fighting soon after the shooting subsided, said hundreds of civilians watched from surrounding hills.

“The sharp rattle of 50,000 muskets and the thunder of a hundred pieces of artillery is not often witnessed,” AP’s correspondent wrote. “It is impossible at this writing to form any correct idea of our losses or that of the enemy. It is heavy on both sides.” AP added that the fighting was so fierce that the dead were “thickly strewn over the field and in many places lying in heaps.”

Tom Sileo is a syndicated columnist. His Unknown Soldiers columns are distributed by Creators Syndicate and appear in the Centre Daily Times on Fridays. Readers may follow his posts on Facebook and his blog at www.unknownsoldiersblog.com.