William Henry Aspinwall (December 16, 1807 – January 18, 1875) was a prominent American businessman who was a partner in the merchant firm of Howland & Aspinwall and was a co-founder of both the Pacific Mail Steamship Company and Panama Canal Railway companies which revolutionized the migration of goods and people to the Western coast of the United States.Aspinwall was descended from, and related to, many prominent American families including the Roosevelts, Howlands, and Aspinwalls, that were heavily involved in the merchant trade business and politics, wielding vast power and ensuring wealth for generations.