He attended the city schools of Philadelphia and later entered the West Point Military Academy where he was graduated in 1904.
After a period of indecision Mr. Hackett decided upon a professional rather than a military career, and began architectural training in the Chicago office of D. H. Burham & Company. Then came the start of World War I, and the young man enlisted in the U. S. Army. He was in active service in France during the Argonne offensive, was raised to the rank of Colonel, and later received the Distinguished Service Medal and other military decorations.
Returning to Chicago after the Armistice in 1918, Mr. Hackett started architectural practice, and for a number of years (1922 to 1934) was a member of Holabird & Root's office. During the latter year he moved to Washington to accept the position of General Manager of the Federal Works Emergency Housing Corporation, and between 1935 and 1937 served as Assistant Administrator of the Public Works Administration. Leaving Government service in 1938 Colonel Hackett established an architectural office in New York where he continued active until the time of his decease.
Quotes from others about the person
He once said of Bradbury Robinson passing "Whew, that chap is a wonder! He beats anything I ever saw. He looks as though 40 yards is dead for him, and he's got accuracy with it."