in 1950 daley became the cook county clerk and he held that office until1955 when he ran for and was elected mayor of chicago. richard j. daley held the office of mayor of chicago until he died on december 20, 1976.

This is all lower case. Can you fix that?
In 1950 Daley became the Cook County Clerk and he held that office until1955 when he ran for and was elected Mayor of Chicago. Richard J. Daley held the office of Mayor of Chicago until he died on December 20, 1976.