John Alanson Dowst was born around 1845 in Maine to Henry and Mary Dowst. His father was a farmer who owned $1,500 of real estate and $956 of personal property by 1860. He grew up and attended school in Vienna, Maine, and by 1860, he was working as a farmer.
He enlisted in the Union army on December 21, 1863, and he mustered in as a private in Battery I of the 1st Maine Heavy Artillery. The regiment took part in the Overland Campaign and the siege of Petersburg. He was wounded in the Battle of Spotsylvania Court House on May 19, 1864, but he eventually recovered. He mustered out on May 22, 1865.
He returned to Maine after the war and attended the Maine Wesleyan Seminary. He married a woman named Ella, and their son Arthur was born around 1873. They moved to Brooklyn, New York, in the 1870s, and Dowst worked as a cider dispenser. According to one local writer, he became “one of the largest producers and dispensers of cider in the country and amassed considerable wealth.” He applied for a federal pension in November 1879 and eventually secured one. He died in Brooklyn on November 30, 1893.