From 1853 to 1861 he worked as an immigration agent for the
Illinois Central Railroad. He returned to Europe to promote emigration to America. President
Abraham Lincoln formally recognized Malmborg as the vice consul of
Norway and
Sweden at Chicago on November 22, 1861. The same year he returned to military service and was appointed as a
lieutenant colonel in the
Union Army. After Stuart resigned on April 3, 1863, Malmborg became the permanent commander until being relieved. He resigned on September 20, 1864. On January 1, 1865, Malmborg was commissioned a colonel in the First Veteran Army Corps under
General Winfield Scott Hancock and was ordered to oversee the recruiting in
Illinois, with headquarters in Chicago once again. He resigned from this position on May 31, 1865. ==Later years==