[1] It was the first company to be awarded a contract by the US government for the oceanic transportation of mail.

[1] Washington and Hermann both suffered mechanical difficulties, and Mills parted ways acrimoniously with the company—after giving control to investors but staying on as a manager, he tried to begin a competing line and was then fired from OSNC.

[2] Both the company's vessels were rebuilt with improved propulsion systems in the early 1850s, but they remained slower than the competition.

[3] After a brief upturn in business in 1855, when Cunard ships were chartered by the British government to serve in the Crimean War, competition returned to the North Atlantic the following year, as Cunard resumed service and German companies Hamburg America Line and Norddeutscher Lloyd began transatlantic crossings from German ports.

[3] In July 1857, after losing its remaining US mail contract for traffic to Germany, OSNC ceased operations.