The Union was a side wheeler launched in Carleton on April 19, 1851. She was the first steamer built for the Union Line and was 135 feet long and had a beam of 20 feet. Her gross tonnage was 53.
She began service early in June between Indiantown and Fredericton. Almost immediately, when nearing Oak Point, she collided with the steamer City of Saint John. The bow of the Union struck the City of Saint John just forward of the port paddle wheel, completely breaking through the guard, through the deck and entering the hull above the waterline, killing some livestock. The City of Saint John was able to continue downriver where she went through the Reversing Falls, to be placed on blocks for repairs. The Union was not badly damaged.
The Union was the first boat to provide regular service to Grand Lake.
The spring of 1854 was notable because of the record floods experienced on the river, the highest since the coming of the settlers. Considerable damage, as well as much hardship, resulted as wharves were under water, which created serious difficulties for the safe operation of the river steamers. This same year there was a tremendous increase in river traffic from Saint John to various points upriver as far as Grand Falls.
This was also the year of the "Gold Rush" to Australia. This drew many young men from the river communities, and they were often accompanied as far as Saint John by family and friends. A late "freeze up" also helped the volume of traffic. On December 10 of that year, the Union was still running between Woodstock and Saint John.
In 1863, the Union was sold to the American government as a blockade runner in the Civil War. Fitted out at great expense and loaded with coal and supplies, she started for Havana. Her captain had refused directions, and on leaving the harbor, headed for the foul ground. She soon grounded, doing considerable damage to her hull. At the time, it was ebb tide. On the next flood tide she floated, drifted off into deeper water, and sank. After several attempts, she was raised with the use of lumber scows and brought back in the harbor. After repairs, she sailed again for Havana and arrived safely. Twice she ran the blockade successfully, but on the third attempt was captured.