Russell Alexander Alger was an American politician and businessman. He served as the 20th governor of Michigan, U.S. Senator, and U.S. Secretary of War. Alger life was a "rags-to-riches" success tale. He became an army officer, financier, lumber baron, railroad owner, and government official in several high offices. He was supposedly a distant relation of author Horatio Alger.

The secretary of war was a member of the U.S. president's Cabinet, beginning with George Washington's administration. A similar position, called either "Secretary at War" or "Secretary of War", had been appointed to serve the Congress of the Confederation under the Articles of Confederation between 1781 and 1789. Benjamin Lincoln and later Henry Knox held the position. When Washington was inaugurated as the first President under the Constitution, he appointed Knox to continue serving as Secretary of War.