Kozlowski was from Chicago[1] and attended Lane Tech high school,[2] where he already proved to be a very fast swimmer, and set a scholastic record in the 100 free.
On March 27, 1943, while swimming for Northwestern University, he broke the world record in the 50 yard freestyle by swimming 22.1 seconds, breaking the 20-year-old record set by Duke Kahanamoku.
[8] Kozloswki entered the United States Army the month after setting his world record.
[8] He indicated in a December 1944 article in a U.S. Army newspaper that he intended to return to college swimming after the war,[8] but it is unclear if he did so.
"[9] Dick Cleveland beat Kozlowski's 50 yard record in early 1954, swimming 21.9 seconds.