After graduation from law school, he entered private practice in Allentown, and began service in the United States Marine Corps Reserve, achieving the rank of Corporal.

[2] Cahn was nominated by President Gerald Ford on November 18, 1974, to a seat on the United States District Court for the Eastern District of Pennsylvania vacated by Judge John Morgan Davis.

[2] Since his retirement from the federal bench, he has served as of counsel to Blank Rome, where he remains active as of November 2023.

[3] He was appointed and approved as Chapter 11 case trustee for the SCO Group on August 25, 2009.

[4] On August 20, 2001, the Edward N. Cahn Federal Building and United States Courthouse in Allentown was renamed in his honor.