William H. Mengel (third from the right) was born in Hessen, Germany, immigrated to the United States, and was living in California, Missouri when the war began. On June 14, 1861, he enlisted as a first sergeant in Company G, Cole County Home Guards (also known as the 1st Regiment U. S. Reserve Corps); in mid-September 1861, he was detailed with 20 men to guard a boatload of supplies from Jefferson City to Lexington, Missouri. During the Siege of Lexington, he was wounded and captured, but was soon paroled.
On October 14, 1861, he enlisted with the 26th Missouri Volunteer Infantry (U.S.), mustering in on January 9, 1862; he was promoted to second lieutenant in June 1862, to first lieutenant in February 1863, and to captain in May 1864. Mengel fought in numerous battles, including Corinth and the Siege of Vicksburg, Mississippi. He was mustered out on January 9, 1865, and returned to California, Missouri.
Image Courtesy Wilson’s Creek National Battlefield; WICR 31359