In 1968, he refused to run for re-election (his successor, Betty Brunk, was Springfield's first female mayor), but remained on the city commission.

After finishing his term as mayor, Henry was selected as a member of a fact-finding commission to Vietnam by order of then-president, Lyndon Johnson, and later returned in 1970 under Richard M. Nixon to inspect non-military activities.

In 1972, he was the Republican Party nominee for the 60th District seat in the Ohio House of Representatives, but lost in the general election.

He also continued to serve as head of charity drives and numerous civic organizations in the Springfield area.

He was honored by a parade and banquet in Springfield on Robert C. Henry Day during Black History Month.