13. Theodore Roosevelt
The 26th President of the United States and the 33rd governor of New York was influential in his day for many reasons, including as a social reformer, a trust buster, a battler of graft and corruption in government, and as the man who led the charge up San Juan Hill. But his greatest influence on the life of Americans, indeed of all the world, was his untiring leadership in the support of the United States completing the Panama Canal after the French gave up. The canal transformed world trade and defense, and continues to do so more than a century after it was completed. It is so critical that during World War II it was given the United States’ highest defense priority.