Two Minnesota teens — separated in life by 60 years, nearly to the day — pulled on military uniforms and soon witnessed two of the most pivotal moments in the history of U.S. warfare.

John O. Dolson, a private with good aim, died in a military hospital in Gettysburg, Pa., on Sept. 3, 1863, two months after the Civil War's bloodiest battle left him with a punctured lung while engaged in a critical Union counterattack on the rock-strewn hill known as Little Round Top.

Frank M. Hajdu was born Sept. 2, 1923. At 18, he joined dozens of St. Paul seamen serving on the USS Ward, a destroyer patrolling Pearl Harbor on the infamous morning of Dec. 7, 1941. When he died last month at 92, Hajdu was believed to be the second-to-last St. Paul survivor from that World War II crew.

On this Memorial Day, let's remember the sharpshooter and the sailor — just two of countless Minnesotans who fought under the U.S. flag.

History lost track of him

Orphaned at an early age, Dolson, a native of central Illinois, was raised on a Richfield Township farm in the late 1850s with his deaf older sister after the family moved to the Territory of Minnesota. Census records list Dolson as a laborer and say he used the Harmony post office in Hennepin County.

Dolson enlisted, at 18, with the First Minnesota Regiment on April 29, 1861, and joined Company A of the 2nd U.S. Sharpshooters. Minnesota was among only four states with two sharpshooter regiments.

Frank Hajdu, 1923-2016

Dolson was wounded with a Minie ball to the lung on the second day of the Gettysburg clash, but we don't know much more. In fact, history lost track of him for nearly 150 years.

But in 2006, researchers unearthed a major typo as they combed through records from Camp Letterman, the military hospital outside Gettysburg where Dolson died.

Dolson was buried near the hospital until 1871, when southern states raised funds to disinter and return Confederate war dead. That's when the sharpshooter from Minnesota headed south by accident.

It turned out that Dolson joined 136 Confederate soldiers whose remains were buried at Oakwood Cemetery in Raleigh, N.C. A headstone in Oakwood was chiseled with the name John O. Dobson of Company A, 2nd North Carolina Infantry — even though muster rolls from the Confederate unit list no such man.

When researchers a decade ago realized it was actually Dolson buried there, a new, rounded headstone — signifying a Union soldier — was added to the sea of pointed stones marking Confederate soldiers' spots.

At 2 p.m. Monday in Richfield's Veterans' Park, a special ceremony will be held to unveil a new marker explaining Dolson's mislaid remains. They still may be in North Carolina, but now both the old "Dobson" gravestone and a new plaque tell his story at a park in his hometown.

Just one survivor left

Hajdu was born and grew up in an immigrant neighborhood near the State Capitol in St. Paul. His father, George, emigrated from Hungary in 1911 and worked in a flour mill. His mother, Emma, was an indentured servant who left Germany about the same time.

With the Great Depression squeezing the family's finances, Frank's mother signed papers so he could drop out of Mechanic Arts High School and join the military in 1940. He was 17, the oldest son.

"The military was about the only entity able to hire anyone," according to his daughter, Lucy Emerson. "He chose the Navy because, as he told it, 'I liked their hat.' ''

Hajdu was among 84 Minnesota naval reservists — most if not all from St. Paul — in the 140-man crew aboard the USS Ward, a World War I-era destroyer. Just after 6:30 a.m. on Dec. 7, 1941, Hajdu was on watch when a plane spotted a miniature Japanese submarine skulking around Pearl Harbor.

Bearing down at 25 knots, the Ward fired a shot, followed by depth charges. An oil slick signaled it had sunk its target.

"We have attacked, fired upon, and dropped depth charges upon submarine operating in defensive sea area," the Ward messaged at 6:53 a.m., only to be ignored. False alarms had been frequent.

The Navy did not go on full alert. The Pearl Harbor attack, pulling the U.S. into World War II, began at 7:55 a.m.

Naysayers scoffed at Ward crew members' claim of sinking a Japanese sub with the first U.S. shots of WWII. But in 2002, 61 years later, researchers found the sunken sub 1,200 feet below the surface — vindicating Hajdu and his mates.

Hajdu returned home and, in 1948, married Jean Mildred Staloch of Wells, Minn.; they had four kids. He re-enlisted — this time in the Army — working as an electrician with the Corps of Engineers in Okinawa, Japan, as part of the U.S. occupying force.

Transferred to a base in Virginia, he was schooled in the new field of nuclear engineering. That sent him to assignments in Greenland and Oak Ridge, Tenn., where he developed a love for the mountains of eastern Tennessee. He bought some land there and in 1989 moved to Campbell County, where he died April 5.

Hajdu donated his body for research. His remains eventually will be buried at Arlington National Cemetery.

With his death, it's believed that only one Ward seaman from St. Paul still survives.

"We were just kids who enlisted at 17 and, as far as I know, I'm the only one left," said Richard Thill, 92, of St. Paul. "There might be others who moved away. But Frank and I were among the youngest and the older ones are gone."

Curt Brown's tales about Minnesota's history appear each Sunday. Readers can send him ideas at mnhistory@startribune.com. A collection of his columns is available as the e-book "Frozen in History" at startribune.com/ebooks.