Helen Fortney of East Jordan, Mich., sent her first letter to Kurt Maybaum of Germany at the age of 17, The Petoskey News-Review reported, as part of a program meant to improve world peace through correspondence.
Fortney was living in southern Michigan at the time, and the two quickly became friends.
"It was a delightful experience because I had never been to Germany," said Fortney. "He would send a lot of pictures and he was very proud of his heritage."
Maybaum, who was 20 when he received the first letter, was a soldier during World War II and had spent time as a prisoner of war.
Their letters were sometimes a few months apart, or sometimes just a few weeks, the News-Review said.
In 1970, after 23 years of writing, Fortney traveled to Amsterdam, Netherlands, and the two met for the first time.
Fortney's husband, Matt, served in WWII in the U.S. Army, and he and Maybaum talked about their stories.
"They started talking about their experience in the war. It was very moving," Fortney said.