He served in the United States Army during World War II from 1942 to 1946.

Following his military service, he pursued higher education at the University of Kansas, earning a Bachelor of Science degree in 1948 and a Bachelor of Laws from the University of Kansas School of Law in 1950.

In 1965, he was appointed as a justice of the Kansas Supreme Court, a position he held until 1971.

[1] On October 19, 1971, O'Connor was nominated by President Richard Nixon to a seat on the United States District Court for the District of Kansas vacated by Judge Arthur Jehu Stanley Jr. O'Connor was confirmed by the United States Senate on October 28, 1971, and received his commission on November 1, 1971.

He served as Chief Judge from 1981 to 1992, assuming senior status on March 1, 1992.