[citation needed] In 1914, O'Connell was appointed to the National Conference on Uniform State Laws by Governor David I. Walsh.

[citation needed] In May 1917, O'Connell was elected to serve as a member of the Massachusetts Constitutional Convention, representing the 12th congressional district.

[citation needed] In 1923, O'Connell served as member of the State commission to revise the charter of the city of Boston in 1923.

[citation needed] O'Connell unsuccessfully ran for United States Senate in 1930 and Mayor of Boston in 1933.

[citation needed] O'Connell died in Boston on December 10, 1942, three days after his 70th birthday and was interred at St. Joseph's Cemetery in West Roxbury, Massachusetts.