A native of Lafayette, Indiana,[1] Overesch attended Purdue University for two years before enrolling as a midshipman at the United States Naval Academy.

[6] In November 1937, he was serving as a naval attache in Shanghai, China, when Japanese forces attacked the city.

Overesch provided the Associated Press with his first-hand account of watching the battle from the upper floors of a Chinese teahouse with the nearest fighting less than 50 yards away.

[14] In June 1944, the San Francisco under Overesch's command participated in the naval battle known as the Marianas Turkey Shoot.

[16] By He served at Pershing Heights, Tokyo, Japan as Chief CIA North Asian Command overseeing covert operations in mainland China, Japan, Hong Kong, North and South Korea, Taiwan, Okinawa, and the Philippines.