Thanks, that helps a lot!
I was able to find several swords with the same makers mark that belongs to Abraham Kuller (Zu Wald) who was a Solingen sword maker active from 1847 to 1880 and marked his blades with a walking bear TM. Also, he exported his swords to Northern & Southern dealers during the Civil War (Source: German Swords and Sword Makers by R. Bezdek). In 1880 Kuller was purchased by WKC. So, most likely this dagger is presentation or gentleman�s dagger that was imported to US from Germany. I will keep researching it, but at least now I know when and by who it was made.