The house flag of the American Mail Line Ltd, Seattle. On a light blue background, there is a yellow disc surrounded with a white band inscribed 'AMERICAN MAIL LINE'. In the centre of the disc is shown a flag striped horizontally in blue, white, red, white and blue. The flag is made of a wool and synthetic fibre bunting. It has a cotton hoist with eyelet holes at the top and bottom. The flag is machine sewn and the design is printed.

H. F. Alexander's Admiral Line started a service between Seattle and the Far East under the name of the Admiral Oriental Mail Line. The company was taken over by the Dollar family in 1922 and re-named the American Mail Line. The Dollar and American Mail Lines were taken over by the government to prevent their bankruptcy in 1938 and the former was re-named American President Lines. American Mail regained its independence at this time. Following privatization after the war, the company was re-acquired, by American President Lines in 1954. The use of the American Mail Lines name and flag ended in 1973.