Augustus Martensen (given name Carl Friedrich Augustus von Martensen), was born in Kiel, an independent town in the Schleswig-Holstein region of northern Germany, in 1822. At 26, he joined the Army of Schleswig-Holstein where he served in the artillery brigades during the First War of Schleswig (1848 to 1851). It appears that he emigrated to the United States at some point after Schleswig-Holstein was returned to Danish control by the Treaty of London in 1852. By 1855, Martensen was living in Litchfield County, Connecticut. There he met and married Rosine Seiz, the young widow of Johann Peter Schering, another German American émigré who had served in the Army of the United States from 1847-1848 during the Mexican War. Schering died in August of 1854; Rosine married Martensen the following March, and two months later the Martensens claimed the bounty land allotted to Schering as a U.S. veteran under an Act of Congress in 1850.
- Augusta, born September 19, 1856
- Carl Friedrich, born August 9, 1858
- Rosa, born October 23, 1860
When the Civil War erupted after the firing on Fort Sumter in April 1861, Martensen immediately joined the First Regiment of Connecticut Volunteers as a Private under Capt. Marcus Coons. The Regiment was soon reconfigured, and Martensen was honorably mustered out as his unit was joined to the New York Cavalry Volunteers in July 1861. He served under Coons in the New York Cavalry Volunteers, rising from Private to the rank of 2nd Lieutenant Colonel in Second Regiment of New York Cavalry before he was killed in action on June 17, 1863, likely on the way to Gettysburg.
From the guide to the Augustus Martensen Papers, Martensen (Augustus) Papers, 1822-1923, (John Hay Library Special Collections)
