Reverting to her old name, "New York", the ship resumed transatlantic service with the American Line until World War I. During this period she underwent extensive conversion in 1903, when one of her three funnels was removed. When United States joined World War I, again needed in support of American forces abroad, "New York" was chartered by the Navy 9 May 1918 for use as a troop transport. She commissioned as "Plattsburg" on 24 May 1918 and commanded by Claude C. Bloch.