She was chartered by the quartermaster corps of the Union Army during the American Civil War to provide logistical support.

Notably, she made five trans-Atlantic voyages and brought several thousand immigrants to the United States from Northern Europe.

She was to supply the Union Army's need for additional seaborne shipping to support military forces along the Confederate coast.

She was built at the Atlantic Marine Railway Company shipyard in Red Hook, Brooklyn, New York under the supervision of Captain F. Z. Tucker.

She arrived the next day to embark the 1st battalion of the 3d Rhode Island Cavalry Regiment which had been ordered to New Orleans.

Despite having only three muskets and no ammunition, Captain William B. Hilton organized a boarding party of passengers and crew that seized the ship.

[13] Western Metropolis made two trips between Boston and Hilton Head, South Carolina to move units of the 4th Massachusetts Cavalry Regiment.

[14] During the first trip, at 4 am on March 24, 1864, Western Metropolis collided with the fishing schooner Triumph near Nantucket, Massachusetts.

In subsequent litigation Western Metropolis was held at fault for the collision for lack of an adequate lookout.

[16] Her first trip as a hospital ship sailed to Newport, Rhode Island where she arrived on June 6, 1864 with 588 wounded soldiers from the Army of the Potomac.

On August 17, 1864 Western Metropolis arrived in New York with 218 white and 239 "colored" soldiers to be distributed to local hospitals.

Western Metropolis participated in the first assault on Fort Fisher, joining the Federal fleet no later than December 17, 1864.

The collision did no damage to Charles Thomas' hull, but her rudder was jammed and Baltic's anchor chain was wrapped around her propeller rendering the ship immobile.

In a grumpy January 1, 1865 telegram, Grant asked that the ship be returned to her hospital duties and sent to Savannah, Georgia to evacuate the sick and wounded from General Sherman's army.

From here, passengers would be transported up the San Juan River, across Lake Nicaragua, and a 15-mile carriage road to reach the Pacific Coast.

Captain Hilton, with the aid of the American Counsel in Havana, managed to prevent such an event, and she sailed on to New York, reaching port on March 18, 1865.

Major General Weitzel was dispatched on the "Texas expedition" to eject the French who had occupied portions of Mexico.

She flew the headquarters flag of the 1st division of the 25th Corps, having on board General Giles A Smith, his staff and two regiments of infantry.

[41] At the end of 1865 Benner and Brown sold Western Metropolis to the Ruger Brothers for their new North American Lloyd Line.

While there were several designs for improved paddlewheels at the time, those used on Western Metropolis were invented and built by W. R. Manley in New York.

When she finally did leave New York bound for Bremen, so many of her paddles broke off the wheels that she was forced to return to Boston where she arrived July 6, 1866.

[45] Temporary repairs were made and Western Metropolis sailed back to New York on July 13, 1866 for more work on her paddlewheels.

[46] In part due to the failure of Western Metropolis to generate any revenue, and the disruption caused by the Austro-Prussian War, the Ruger Brothers were unable to pay the mortgages on their ships.

[48][49] After Western Metropolis' failed trans-Atlantic trip, the first order of business for her new owners was to fix her paddlewheels.

She went to sea with a collection of prominent engineers on February 13, 1867 for a trial of her new equipment and her captain was told to not come back until they had experienced heavy weather in order to thoroughly test the repairs.

[51] Western Metropolis made two more uneventful roundtrips to Bremen, but on her fourth trip she limped into Southampton on September 8, 1867 with a broken shaft.

Stiff competition in the trans-Atlantic trade from foreign-flagged vessels had the New York and Bremen Line idling ships as early March 1868.

Her wooden hull, side-wheel propulsion, and nearly 30 year-old engine were obsolete technologies that left her unable to compete with more modern ships.

She cleared New York on May 18, 1870 for a sweep of Northern European ports including Le Havre, Bremen, Copenhagen, Swinemunde, Kiel, and Kristiansand.

[62] Notwithstanding this misadventure, the ship was able to complete her voyage, and she arrived back in New York on July 7, 1870 with a full load of 954 immigrants.