Pfaffenschlager enlisted in the Confederate army in 1861 in New Madrid, Missouri and made a name for himself as a talented bugler. His friend William Hartmann of the 38th Alabama Infantry arranged for his transfer to that regiment from the Tennessee Light Artillery so that he could become part of the regimental band.
Pfaffenschlager became chief musician, having the opportunity to demonstrate his skills not only on the bugle, but also with the piano, violin, fife and guitar and transcribed tunes he heard in his travels. He also excelled as an artist, with officers pooling money to buy his ornamented drawing of the regimental headquarters to give as a gift to their Colonel Charles T. Ketchum.
Pfaffenschlager served with distinction through the remainder of the 38th's campaign. He carried a heavy hunting rifle with a large bore and a specially-made bullet mold. He fought at Chickamauga, Lookout Mountain, Missionary Ridge, Rocky Face Mountain and later the Battle of Spanish Fort, where he was one of 80 who survived and accompanied General Richard Taylor to their surrender at Citronelle.
After the war's end, Pfaffenschlaeger married a widow with two daughters and settled in Birmingham to teach music under the name "Professor Pfaffenschlager". In 1882, while talking with friends, he suddenly produced a Derringer pistol and shot himself through the right temple.
After his death, a friend told the Mobile Daily Register that Pfaffenschlager was actually an Austrian noble, Lord Franciscus Adolphus Seeau, who opposed Emperor Franz Joseph and narrowly escaped the country with his life after the revolution of 1848. This identification has been characterized as doubtful by Austrian authorities on the Seeau nobility.
Pfaffenschlager is buried under a large obelisk at Oak Hill Cemetery, which he shares with his widow and her first husband and numerous descendants.
- Green, Art (n. d.) "Frank Pfaffenschlaeger, Forgotten CSA Soldier - An Unusual Man with an Unusual Name" reprint of article published in the Civil War Courier and in Green's Southerners at War - the 38th Alabama Infantry Volunteers.