 He participated in the arrest of the Missouri State Militia at Camp Jackson on May 10, 1861, and wrote a letter to Lincoln with a description of the subsequent shooting of civilians under riot conditions.When Lyon (now a Brigadier General) moved into the interior of Missouri in June, Boernstein commanded the force occupying Jefferson City, the state capital.After the expiration of three months' federal service, Boernstein was appointed United States Consul in Bremen, Germany, by President Lincoln, although he returned briefly to St. Louis in 1862 in a vain attempt to save Blair's Congressional seat for the Republican Party.