He received an appointment to West Point from Iowa, graduating first in his class in 1897; his Cullum number is 3742.

He led the brigade at the Battle of Château-Thierry in mid-1918, with his performance resulting in him being awarded a second Silver Star, the citation for which reads: By direction of the President, under the provisions of the act of Congress approved July 9, 1918 (Bul.

Brigadier General Connor distinguished himself by gallantry in action while serving as Commanding General, 63d Infantry Brigade, American Expeditionary Forces, in action near Mont St. Martin, France, 3 August 1918, in personally directing and controlling the attack under severe shell fire.

The citation for the medal reads: The President of the United States of America, authorized by Act of Congress, July 9, 1918, takes pleasure in presenting the Army Distinguished Service Medal to Brigadier General William Durward Connor, United States Army, for exceptionally meritorious and distinguished services to the Government of the United States, in a duty of great responsibility during World War I.

As Chief of Staff of the 32d Division in the trench operations in the Belfort sector and later as Commander of the 63d Infantry Brigade in the advance to the Vesle he displayed particular ability as a leader of troops.