Gillian Brockell wrote in an article at the WP:
In 1860, two major factors helped to propel Lincoln — a one-term congressman and country lawyer most known for losing a Senate campaign — to the Republican nomination for the presidency. First, the support of former German revolutionaries who had become key players in the Republican Party; and second, the support of the party’s newspaper, the Tribune.
So, who were these former German revolutionaries? A quick search did not locate names.