Austin Fosdick was born on September 26, 1823, in Indiana. He married Rebecca Hollingsworth on January 15, 1844. They had one son, but he died in infancy. They lived in Red Rock, Iowa, and Fosdick worked as a farmer. By 1860, he owned $400 of personal property.
He enlisted in the Union army on August 11, 1862, and he mustered in as a private in Company H of the 40th Indiana Infantry on October 20. The regiment took part in the Tullahoma campaign, the Battle of Chickamauga, the Battle of Missionary Ridge, the Atlanta campaign, and the Battle of Nashville. He mustered out on August 2, 1865.
Fosdick moved to Ashland, Nebraska, after the war. He applied for a federal pension in October 1883 and eventually secured one. His wife’s health deteriorated in the early 1900s, and she was admitted to a mental health facility in 1910. She died there on February 6, 1911. Around the same time, Fosdick was admitted to a National Home for Disabled Volunteer Soldiers in Grand Island, Nebraska. He died in Ashland on February 25, 1914.