At the start of the Civil War in 1861, my great-great-grandfather, Constantine Kollros, was 23 years old. Yet, up until yesterday, I was unable to determine which side of the battlefield he was on or whether he served not at all. According to the US census of 1860, Louisville, Kentucky, Constantine was employed as a musician. For years, I searched through Kentucky and Ohio muster rolls for both the Confederate and Union forces. Neither Constantine nor his brother Dominic appeared on any of the lists I searched.

Statistically speaking, as a German Catholic living in Louisville, he would most likely have been in the Union Army.

German-Americans were the largest ethnic contingent to fight for the Union in the American Civil War. More than 200,000 native-born Germans, along with another 250,000 1st-generation German-Americans, served in the Union Army, notably from New York, Wisconsin, and Ohio. Only a few hundred served in the Confederacy, being primarily 3rd- and 4th-generation descended from those who had migrated to the Carolinas in the 18th and early 19th centuries.

German Americans in the American Civil War – Wikipedia

Now, I have determined that he did at least register for the draft, and in fact, it was only a few days after Pres. Lincoln ordered draft registration to begin. According to the document, I found Constantine registered for the first Federal draft on July 3, 1863 during Draft Week, at Louisville, Jefferson County, Kentucky.