He was a supporter of the Treaty and became leader of the provisional government's army in the Civil War which followed.
Mulcahy served as Irish Defence Minister from 1923-1924. He became leader of Fine Gael in 1944, however, he was forced to decline becoming Taoiseach on two occasions because he was seen to be an unacceptable candidate. Instead he served as Minister for Education from 1948-1951 and 1954-1957. Mulcahy retired as Fine Gael leader in 1959.
Richard Mulcahy died in 1971.