The tug Alfred Mosher was built in 1863 by the Miller Brothers & Clark shipbuilders in Chicago, Illinois. At this time, the ship was owned by Mosher & Dunham and was valued at $7,000. Throughout its operation, it was used to aid distressed and stranded vessels on the Great Lakes and occasionally was chartered to carry cargo. Prior to the 1880s, historical record of Alfred Mosher's movement is minimal.

On February 1, 1881, the Alfred Mosher suffered damage while attempting to break the schooner Queen City out of the ice near Chicago. It shortly filled with water and sank in thirteen feet of water. Lines leading to the vessel on one side and to the tug Flossie Thielcke on the other held the Alfred Mosher upright. The ship was successfully raised two days later and was placed in dry dock for repairs. In 1883, the Cleveland-based newspaper The Marine Record reported the dissolution of Mosher & Dunham firm after 28 years. The May 12 issue states Alfred Mosher sold "his half of the interest in the Dunham & Mosher fleets to Mr. Dunham, who is now the sole owner." Aside from the Alfred Mosher, the fleet included Wells Burt, Pensaukee, Lottie Wolf, Moses Gage, F.J. King, A. Miller, Robbie Dunham, and Uncle Sam.

Early in the 1890 season, the Alfred Mosher received new machinery from the tug Batchelder. It also received new upper works and a smokestack.
At the time of its demise, the Alfred Mosher was owned by John Walker, Henry Dumann, and William Helmholtz of Sturgeon Bay, Wisconsin. The Alfred Mosher had been chartered by Captain Peter Peterson of Menominee for raft towing. The crew made port at Sturgeon Bay on May 15, 1897, to visit with their families. While docked, the Alfred Mosher was left under watch of the fireman. However, the vessel caught on fire during the night, cause unknown, and went undetected until 3am. By the time the fire crew arrived at the scene, the pilothouse was gone and the entire hold was ablaze. The tug Nelson moved the burning ship from Cromwell's Dock to the east side of the slip; it proceeded to pour water over the Alfred Mosher until it filled and sank. The boiler and engine were in good condition, but no salvage effort was organized at the time. The vessel was valued at $3,000.

The abandoned hull settled into the bottom until it was barely visible. The boiler was salvaged by Captain Thomas Isabell during the summer of 1912. In 1933, over thirty years after the Alfred Mosher sank, dredging operations at the Peterson Boat Works dragged up part of Alfred Mosher's stern. The machinery was reportedly removed at this time.
The wreck of the Alfred Mosher is located at Cromwell's Dock in Sturgeon Bay, on the east side of the mill slip. While the stern was snagged during dredging and machinery removed in 1933, the hull was allowed to sink back into the mud bottom. The site of the Peterson Boat Works is now the CenterPointe Marina.