Matthew B. Mason was born around 1829 in New York. He eventually moved to Aurora, Indiana, and he married Emily Spidell on June 4, 1856. They had at least four children: Nettie, born around 1857; Luella, born around 1860; John, born around 1865; and Elizabeth, born around 1867. He worked as an engineer, and by 1860, he owned $1,500 of real estate and $500 of personal property.
In August 1861, he received a commission as a 1st lieutenant in Company D of the 3rd Indiana Cavalry. The regiment took part in the Second Battle of Manassas and the Battle of Antietam. He was promoted to captain in July 1862, and he mustered out on October 3, 1862. He later served in the 12th Regiment of the Indiana Legion, a state militia unit.
He moved to Cochran, Indiana, after the war, and he worked as an engine builder and machinist. He applied for a federal pension in September 1869 and eventually secured one. By 1870, he owned $3,000 of real estate and $300 of personal property. His wife died in September 1875, and he moved to Kansas City, Missouri, sometime in the 1870s. He married Carrie H. Miller on October 30, 1880. In early 1890, he received an appointment as town elevator inspector. A local writer noted that Mason was “well qualified by years of mechanical experience to fill the position to which the mayor…appointed him.” He died on February 3, 1898.