Cornelius and Richard Poillon operated a shipyard in Brooklyn, New York at the foot of Bridge Street on the East River.

[2] In any case, shortly after her launch on October 6, 1864[3] she was chartered for use by the Quartermaster Corps of the Union Army to provide logistical support along the Atlantic coast for Civil War operations.

A salon 145 feet (44 m) long enclosed on the main deck forward provided space for passenger meals, walking, and entertainments.

[6] She left Hilton Head, South Carolina on March 7, 1865 and encountered heavy weather off Cape Hatteras.

These were mostly armorers from the Fayetteville, North Carolina arsenal, who had relocated from Harpers Ferry, Virginia when the Confederate States moved the equipment they had captured.

[17] On April 6, 1865 she arrived at Fortress Monroe from Moorehead City carrying a "large number" of Confederate prisoners and refugees from General Sherman's campaign.

[20] She was commanded by Captain Cornelius Godfrey[21] in her late war service, her repositioning to the Pacific, and in her early commercial voyages from San Francisco.

[8] At some point prior to her arrival in San Francisco, Ajax was sold to the firm of Wakeman, Gookin & Dickinson, a New York City-based steamship company.

[22] Ajax was moved to Crowell's Wharf to begin a short refitting, for her new owners intended to use her to establish the first scheduled steamship service between San Francisco and Honolulu.

[24] She left San Francisco on January 13, 1866 with 68 passengers, including Samuel Clemens, who reported on the trip using his pen name, Mark Twain.

She carried 34 passengers on this return voyage and a wide variety of agricultural imports including 2,579 kegs of sugar, 807 packages of molasses, 242 sacks of coffee, and 3,621 coconuts.

[27] She arrived back in San Francisco on April 15, 1866[28] with 617 tons of freight, a record for the time for a single ship from Hawaii.

Shortly after her return to San Francisco, the California Steam Navigation Company withdrew he from her Hawaii route, ending scheduled steamship service to the islands.

[33] She made several additional roundtrips between San Francisco and Portland in 1867, but with competition from the Ben Holladay's California, Oregon & Mexico Steamship Company and the newly launched Anchor Line, the route had too many ships on it and a full scale fare war broke out.

The company suspended this transpacific service during the stormy winter months, reassigning the ship to the San Francisco - Portland route.

She resumed her trips to Honolulu on March 18, 1871, carrying 33 passengers, more than half of whom were transferring there to a steamer that would take them to Australia or New Zealand.

Sometime in early 1872, Ben Holladay placed the steamers Ajax, J. L. Stephens, and Oriflamme in a new corporation, the Oregon Steamship Company.

[40] This new company served only the San Francisco to Portland route and thus buttressed Holladay's riverboat and railroad business in Oregon.

[43] The difficulties of the San Francisco - Portland route combined with the Ajax's advancing age brought a cascade of mechanical problems.

[51] In November 1880 she was purchased by Charles Goodall, a partner in the Pacific Coast Steamship Company, one of the significant shipping firms based in San Francisco.

Ajax drops out of newspaper accounts and US Government ship records after 1880, suggesting that she was either broken up, or pursued her new trade as a collier in another country.