He conducted experiments and research with weapons and vehicles in the late 1930s, and was responsible for training soldiers and units for deployment to the North African Theater at the start of World War II.

Kowalski was born in Meriden, Connecticut, on October 18, 1907[1] the son of Polish immigrants Frank and Mary (Miller) Kowalczyk.

[3] He earned a 1926 appointment to the United States Military Academy through a competitive examination administered to eligible enlisted soldiers, and graduated from West Point in 1930.

[2] Kowalski's initial assignment was at Fort Holabird, Maryland, a research and development center for Army vehicles, where he attended the Transportation course for officers.

[3] While conducting a live fire exercise with armor-piercing ammunition, Kowalski was struck by a ricochet; the "spent" round hit his cheek and left him with a permanent scar.

[3] During this assignment, Kowalski received several patents for military weapons and equipment, and also became a member of the newly organized American Rocket Society.

[5] In 1944, he became Director of the London-based Disarmament School for the US Army, a secret program in which selected senior officers received instruction on methods to use in quickly de-militarizing Germany after the war and beginning its political, economic, and social restoration.

[5] In late 1944, Kowalski returned to the United States for training at the Pentagon and post-graduate studies in foreign affairs at Columbia University in preparation to assume duties as a military attaché in Moscow.

[5] He became ill in 1945, and required operations that included removal of most of his stomach; Kowalski convalesced at Walter Reed Hospital for 18 months until late 1946.

Clever political maneuvering overcame strong pacifist opposition as well as efforts to insert the Japanese militarist World War II officer cadre into the leadership of the defense force.

[9] Elected to represent Connecticut in an extra, at-large seat[7] Kowalski maintained a liberal voting record in Congress; as a member of the Armed Services Committee, he was often critical of alleged waste and mismanagement, and the misuse of military personnel for jobs including driver and waiter for senior officers.

[9] On this panel, Kowalski and fellow member Francis Cherry often worked in tandem to prevent the board from violating civil liberties in its efforts to identify pro-Communist employees of the federal government.

[9] He continued to work on inventions, and the day before his death he received a patent for a dual-flush toilet system that he designed to conserve water.