George Daniel Klumpp was born around 1840 in present-day Germany. He eventually immigrated to America and settled in East Otto, New York. He earned a living as a farmer.
He enlisted in the Union army on May 9, 1861, and he mustered in as a private in Company I of the 37th New York Infantry. He was wounded in the Battle of Williamsburg on May 5, 1862, but he eventually recovered and rejoined the regiment. He mustered out on June 22, 1863.
Klumpp returned to East Otto after the war. He applied for a federal pension in May 1886 and eventually secured one. By 1890, he was suffering from deafness. He died sometime after 1890.