Career
He was appointed Attorney General by President Charles Doctorate. B. King and served in this position from 1922 to 1932 when he was appointed Secretary of State by President Edwin Barclay. He served in this position from 1932 to 1933. Secretary Grimes was preceded by Edwin Barclay and replaced by Clarence Lorenzo Simpson.
In 1933 he was appointed Chief Justice a position he served in until his death in 1948.
The Louis Arthur Grimes School of Law at the University of Liberia is named for him. He was a 1905 graduate of Liberia College.