He was also a political activist, author, soldier, actor and stage manager, and was briefly yet closely acquainted with Karl Marx during his tenure as publisher of the radical newspaper Vorwärts.

His family fled from Hamburg, his native city, to Lemberg (then in Austrian Galizia, now L'viv in Ukraine) in 1813, due to fighting between allied and French forces.

After leaving the university, Boerrnstein joined an Austrian army regiment stationed in Olmütz, Moravia, for five years, before resigning his commission as a cadet and going to Vienna.

After a period in Vienna, Boernstein went on tour as an actor to cities in the Austrian Empire such as Budapest, Lubjana, Agram [Zagreb], Trieste and Venice, and he served as supervisor of the municipal theaters in St. Pölten and Linz.

Boernstein wrote articles for Horace Greeley's New-York Tribune (translated into English by Charles Anderson Dana and Bayard Taylor) as well as for German journals in America such as the Deutsche Schnellpost of New York.

[4] At the time of the February 1848 revolution in Paris, he became president of the Société des Democrats Allemands, helping to organize a military unit under Georg Herwegh to aid the revolt in Baden.

"[10] Boernstein became an early supporter of the newly founded Republican Party, and he dramatized the fact that John Frémont was not on the ballot in Missouri in 1856 by having his followers vote for the Know-Nothing presidential candidate Millard Fillmore "under protest,"[11] since the nativist position was incidentally in tune with his hostility to Catholicism.

[13] In the months before Abraham Lincoln's inauguration, political tensions in St. Louis deteriorated into armed confrontation, while pro-Southern elements plotted to seize the United States Arsenal.

[14] 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.

[15] When Lyon (now a Brigadier General) moved into the interior of Missouri in June, Boernstein commanded the force occupying Jefferson City, the state capital.

[16] 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.