On July 2, 1881, at the age of 15, he and his 17-year-old brother, Harry Augustus Garfield, witnessed the shooting of their father by disgruntled office-seeker Charles J. Guiteau at the Baltimore and Potomac railroad station in Washington.

The President and his sons were waiting for a train en route to Williams College in Williamstown, Massachusetts, where young James had been recently accepted, when the shooting took place.

He was an influential advisor to President Theodore Roosevelt, serving as a Member of the United States Civil Service Commission from 1902 to 1903.

From 1903 to 1907, he served as Commissioner of Corporations at the Department of Commerce and Labor, where he conducted investigations of the meat-packing, petroleum, steel, and railroad industries.

From 1907 to 1909, he served in Roosevelt's Cabinet as Secretary of the Interior, where he advocated for the conservation of natural resources but, notably, approved the request from San Francisco to dam the Hetch Hetchy valley in Yosemite National Park.

[3] Garfield died in Cleveland, Ohio,[4] on March 24, 1950, at the age of 84, and was the last surviving member of President Theodore Roosevelt's cabinet.