The Steam Packet and U.S. mail boat Columbia, Capt. Leach, from this port, has arrived at Mobile, and was to begin to run between that place and New Orleans in a few days, three times a week. She will carry the mail, and can accommodate 50 passengers in an elegant cabin. The boat is coppered and copper fastened to the bends, 105 feet keel, 131 tons burthen, and has a low pressure engine.