He resigned after being impeached by the United States House of Representatives due to allegations of alcoholism.

[2] Delahey had a personal friendship with Abraham Lincoln originating with their mutual cause in establishing the Republican Party.

Instead of approaching Lane directly, as Delahay asked, Lincoln sought to accomplish the desired end by a somewhat circuitous, but equally effective route.

His daughter, Mary E. Delahay, is authority for the statement that Lincoln offered to appoint him Minister to Chile, which post he declined.

The investigating committee reported to the House of Representatives that Delahay’s "personal habits unfitted him for the judicial office .