He engaged in mineral explorations of the Lake Superior copper and iron regions in connection with the Michigan State Geological Survey 1845–1847.

He engaged in the practice of law in Port Huron, Michigan, in 1848 and was elected judge of the St. Clair County Court in 1850.

He was a member of the State military board during the Civil War, holding the rank of colonel.

After leaving Congress, he engaged in the practice of law in Washington, D.C., and died in Ocean City, Maryland.

Conger also played an important role in the establishment of the American Red Cross.

The 15 people present at this meeting include Barton, Conger, and Rep. William Lawrence (R, OH).

His grandson was also named Omar Dwight Conger and graduated from Harvard University before being killed in San Diego during World War II.