His father, William, took his own life in January 1897, ostensibly due to failure of the First National Bank of Illinois, which he had founded.

[4] Hammond studied mechanical engineering at Cornell University, and was a member of the Delta Upsilon fraternity.

[5] When the United States entered World War I, Hammond served with the 16th Regiment Engineers (Railway), American Expeditionary Force, in France.

[3] A partner in the company, Col. John H. Poole, with whom he had served in France, knew of his engineering skills, and paid him an extra $300 a week under the table to stay with Gray Motor.

[7][better source needed] This invention brought him enough money to leave Gray Motor Company and rent his own space in New York City.

He premiered this show at the Selwyn Theatre in New York in December 1922 to critical acclaim, but the cost of installing the expensive machinery in the theater was prohibitive, and the process was never used again.

The company's assistant treasurer, W. L. Lahey, was the organist at the nearby St. Christopher's Episcopal Church, and Hammond consulted him concerning the quality of the new instrument's sound.

At that time, unemployment was a major problem due to the Great Depression, and with this in mind, the Patent Office rushed to grant his application,[11] with the hope of creating jobs in the area.