Marinus Heyboer, the son of Dutch immigrants John and Cornelia Heyboer, was born in Wallington, New Jersey, on August 20, 1892, and later lived in East Rutherford, New Jersey. He had eight siblings, including Abraham, Gertn, Harry (b. June 1885), Josephine, Harrietta, and Cornelia. Heyboer joined the United States Army before February 1918, and trained at Camp Dix, New Jersey, with Battery B of the 308th Field Artillery Regiment, and, later, with the 310th Field Hospital. He was transferred overseas after April 1918. After the war, he returned to New Jersey, and eventually settled in Caldwell Township with his wife, Lola. He died in August 1969. His brother Harry lived with his wife Marie in Newark, New Jersey, during World War I. They had one son, Harry Heyboer, Jr.