At its height in the 1920s, the Dollar Steamship Company was the largest and most successful United States shipping firm, and its signature white dollar sign mounted on red-banded stacks was known around the world.

In 1901, Dollar now well into his fifties incorporated the Dollar Steamship Company formally entering the steamship business. More importantly, it is at this time that he began to pursue with passion opening up trade with China. In 1902 he took the first of what would be more than 30 transpacific voyages to explore the possibility of trade. 

In the early 1920s, Dollar began a successful strategy of buying shares in his competitors in order to achieve controlling interests. His influence and accomplishments continued to grow. In 1920 he established a round-the-world cargo service, and in 1924 he established the first round-the-world passenger service to publish scheduled departure and arrival times. In 1925 the Dollar Steamship Company took over its chief competitor, Pacific Mail, which gave it a near-monopolistic share of U.S. Pacific coast shipping.

The late 1920s would turn out to be the peak of Dollar's shipping fortunes. The Merchant Marine Act of 1928 established generous subsidies for carrying mail. The Act, however, had strict performance requirements and Dollar would need new ships. The company began an ambitious plan of building six luxurious ocean liners. Before the first ships rolled off the line, the onset of the Great Depression sent the global economy into chaos. Only two of the ships would be completed, the President Hoover and the President Coolidge, which famously set out on their respective maiden voyages at less than half capacity.

during the depression the company was taken over by the U. S. Maritime Commission. The company would soon be reincarnated as American President Lines.